Order Code RL33548
Comprehensive Nuclear-Test-Ban Treaty:
Background and Current Developments
Updated May 28, 2008
Jonathan Medalia
Specialist in National Defense
Foreign Affairs, Defense, and Trade Division

Comprehensive Nuclear-Test-Ban Treaty:
Background and Current Developments
Summary
A comprehensive nuclear-test-ban treaty (CTBT) is the oldest item on the
nuclear arms control agenda. Three treaties currently bar all but underground tests
with a maximum force equal to 150,000 tons of TNT. The Natural Resources
Defense Council states the United States conducted 1,030 nuclear tests, the Soviet
Union 715, the United Kingdom 45, France 210, and China 45. The last U.S. test
was held in 1992; Russia claims it has not tested since 1990. In 1998, India and
Pakistan announced several nuclear tests. Each declared a test moratorium; neither
has signed the CTBT. North Korea conducted a nuclear test in 2006.
Since 1997, the United States has held 23 “subcritical experiments” at the
Nevada Test Site, most recently on August 30, 2006, to study how plutonium
behaves under pressures generated by explosives. It asserts these experiments do not
violate the CTBT because they cannot produce a self-sustaining chain reaction.
Russia has reportedly held some since 1998, including several in 2000.
The U.N. General Assembly adopted the CTBT in 1996. As of May 28, 2008,
178 states had signed it; 144, including Russia, had ratified; and of the 44 that must
ratify the treaty for it to enter into force, 41 had signed and 35 had ratified. Five
conferences have been held to facilitate entry into force, most recently in 2007.
In 1997, President Clinton sent the CTBT to the Senate. In October 1999, the
Senate rejected it, 48 for, 51 against, 1 present. It is on the Senate Foreign Relations
Committee’s calendar. It would require a two-thirds Senate vote to send the treaty
back to the President for disposal or to give advice and consent for ratification.
The Bush Administration opposes the CTBT, adheres to the test moratorium,
has not ruled out resumed testing, and has no plans to test. It has reduced the time
needed to conduct a nuclear test. Critics raised concerns about the implications of
these policies for testing and new weapons.
At present, Congress addresses nuclear weapon issues in the annual National
Defense Authorization Act and the Energy and Water Development Appropriations
Act. Congress considers the Stockpile Stewardship Program (listed as Weapons
Activities), which seeks to maintain nuclear weapons without testing. The FY2008
appropriation for it is $6.356 billion; the FY2009 request is $6.618 billion. Congress
also considers a U.S. contribution to a global system to monitor events that might
violate the CTBT. The FY2008 appropriation was $23.8 million; the FY2009
request is $9.9 million. U.S. voting rights in the CTBT Organization Preparatory
Commission were suspended on January 1, 2008 for not paying enough dues. The
United States paid $23.8 million on February 25, restoring its voting rights.
This report will be updated. For a detailed analysis of pros and cons, see CRS
Report RL34394, Comprehensive Nuclear-Test-Ban Treaty: Issues and Arguments,
by Jonathan Medalia.

Contents
Most Recent Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
National Positions on Testing and the CTBT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
The North Korean Nuclear Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
The CTBT: Negotiations and Key Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Preparing for Entry into Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Suspension of U.S. Voting Rights in the Preparatory Commission . . . 20
Stockpile Stewardship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
CTBT Pros and Cons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Legislation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Chronology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
For Additional Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Appendix. Chronology, 1992-2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
List of Tables
Table 1. U.S. Nuclear Tests by Calendar Year . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Comprehensive Nuclear-Test-Ban Treaty:
Background and Current Developments
Most Recent Developments
In a speech on May 27, Senator John McCain said he would “begin a dialogue
with our allies, and with the U.S. Senate, to identify ways we can move forward to
limit testing in a verifiable manner that does not undermine the security or viability
of our nuclear deterrent. This would include taking another look at the
Comprehensive Test Ban Treaty to see what can be done to overcome the
shortcomings that prevented it from entering into force.” Senators Hillary Clinton
and Barack Obama have made statements in support of the treaty. On March 3-5,
scientists from 30 nations met in Vienna, Austria, to launch an evaluation of the
CTBT detection system, with the results due to be presented in June 2009. On
February 25, 2008, the United States paid the Comprehensive Nuclear-Test-Ban
Treaty Organization Preparatory Commission $23.8 million, restoring its voting
rights in the commission. In January, Barbados, Colombia, and Malaysia ratified the
CTBT. On December 17, 2007, Representative Tauscher introduced H.Res. 882,
“[e]xpressing the sense of the House of Representatives that the Senate should
initiate a bipartisan process to give its advice and consent to ratification of the
Comprehensive Nuclear-Test-Ban Treaty.” On December 6, the conference report
on H.R. 1585, the FY2008 defense authorization bill, was ordered to be printed. The
bill provided for biennial reports on U.S. nuclear test readiness and dropped a
provision in the Senate bill expressing the sense of Congress that “the Senate should
ratify” the CTBT. On December 5, by a vote of 176 for, 1 against (United States),
and 4 abstentions, the U.N. General Assembly adopted resolution A/RES/62/59
stressing the importance of achieving the earliest entry into force of the CTBT.
History
A ban on nuclear testing is the oldest item on the arms control agenda. Efforts
to curtail tests have been made since the 1940s. In the 1950s, the United States and
Soviet Union conducted hundreds of hydrogen bomb tests. The radioactive fallout
from these tests spurred worldwide protest. These pressures, plus a desire to reduce
U.S.-Soviet confrontation after the Cuban Missile Crisis of 1962, led to the Limited
Test Ban Treaty of 1963, which banned nuclear explosions in the atmosphere, in
space, and under water. The Threshold Test Ban Treaty, signed in 1974, banned
underground nuclear weapons tests having an explosive force of more than 150
kilotons, the equivalent of 150,000 tons of TNT, 10 times the force of the Hiroshima
bomb. The Peaceful Nuclear Explosions Treaty, signed in 1976, extended the
150-kiloton limit to nuclear explosions for peaceful purposes. President Carter did
not pursue ratification of these treaties, preferring to negotiate a comprehensive test

CRS-2
ban treaty, or CTBT, a ban on all nuclear explosions. When agreement seemed near,
however, he pulled back, bowing to arguments that continued testing was needed to
maintain reliability of existing weapons, to develop new weapons, and for other
purposes. President Reagan raised concerns about U.S. ability to monitor the two
unratified treaties and late in his term started negotiations on new verification
protocols. These two treaties were ratified in 1990.
With the end of the Cold War, the need for improved warheads dropped and
pressures for a CTBT grew. The U.S.S.R. and France began nuclear test moratoria
in October 1990 and April 1992, respectively. In early 1992, many in Congress
favored a one-year test moratorium. The effort led to the Hatfield-Exon-Mitchell
amendment to the FY1993 Energy and Water Development Appropriations Bill,
which banned testing before July 1, 1993, set conditions on a resumption of testing,
banned testing after September 1996 unless another nation tested, and required the
President to report to Congress annually on a plan to achieve a CTBT by September
30, 1996. President George H.W. Bush signed the bill into law (P.L. 102-377)
October 2, 1992. The CTBT was negotiated in the Conference on Disarmament. It
was adopted by the U.N. General Assembly on September 10, 1996, and was opened
for signature on September 24, 1996.1 As of May 28, 2008, 178 states had signed it
and 144 had ratified.2
National Positions on Testing and the CTBT
United States: Under the Hatfield-Exon-Mitchell amendment, President Clinton
had to decide whether to ask Congress to resume testing. On July 3, 1993, he said,
“A test ban can strengthen our efforts worldwide to halt the spread of nuclear
technology in weapons,” and “the nuclear weapons in the United States arsenal are
safe and reliable.” While testing offered advantages for safety, reliability, and test
ban readiness, “the price we would pay in conducting those tests now by undercutting
our own nonproliferation goals and ensuring that other nations would resume testing
outweighs these benefits.” Therefore, he (1) extended the moratorium at least
through September 1994; (2) called on other nations to extend their moratoria; (3)
said he would direct DOE to “prepare to conduct additional tests while seeking
approval to do so from Congress” if another nation tested; (4) promised to “explore
other means of maintaining our confidence in the safety, the reliability and the
performance of our own weapons”; and (5) pledged to refocus the nuclear weapons
laboratories toward technology for nuclear nonproliferation and arms control
verification. He extended the moratorium twice more; on January 30, 1995, the
Administration announced his decision to extend the moratorium until a CTBT
entered into force, assuming it was signed by September 30, 1996.
1 For treaty text and the State Department’s analysis, see [http://www.state.gov/t/isn/
trty/16411.htm].
2 For a current list of signatures and ratifications, see the Comprehensive Nuclear Test-Ban-
Treaty Organization website at [http://www.ctbto.org].

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On September 22, 1997, President Clinton submitted the CTBT to the Senate.
He asked the Senate to approve it in his State of the Union addresses of 1998 and
1999. Senate Foreign Relations Committee Chairman Helms rejected that request,
saying that the treaty “from a non-proliferation standpoint, is scarcely more than a
sham” and had low priority for the committee. In summer 1999, Senate Democrats
pressed Senators Helms and Lott to permit consideration of the treaty. On September
30, 1999, Senator Lott offered a unanimous-consent request to discharge the Senate
Foreign Relations Committee from considering the treaty and to have debate and a
vote. The request, as modified, was agreed to. The Senate Armed Services
Committee held hearings October 5-7; the Foreign Relations Committee held a
hearing October 7. It quickly became clear that the treaty was far short of the votes
for approval, leading many on both sides to seek to delay a vote. As the vote was
scheduled by unanimous consent, and several Senators opposed a delay, the vote was
held October 13, rejecting the treaty, 48 for, 51 against, and 1 present. At the end of
the 106th Congress, pursuant to Senate Rule XXX, paragraph 2, the treaty moved to
the Senate Foreign Relations Committee calendar, where it currently resides.
The Nuclear Posture Review and Nuclear Testing: In the FY2001 National
Defense Authorization Act (P.L. 106-398, Sec. 1041), Congress directed the
Secretary of Defense, in consultation with the Secretary of Energy, to review nuclear
policy, strategy, arms control objectives, and the forces, stockpile, and nuclear
weapons complex needed to implement U.S. strategy. Although the resulting
Nuclear Posture Review is classified, J.D. Crouch, Assistant Secretary of Defense for
International Security Policy, presented an unclassified briefing on it on January 9,
2002, dealing in part with the CTBT and nuclear testing.3 He stated there would be
“no change in the Administration’s policy at this point on nuclear testing. We
continue to oppose CTBT ratification. We also continue to adhere to a testing
moratorium.” Further, “DOE is planning on accelerating its test-readiness program”
to reduce the time needed between a decision to test and the conduct of a test, which
was then 24 to 36 months. He discussed new weapons. “At this point, there are no
recommendations in the report about developing new nuclear weapons ... we are
trying to look at a number of initiatives. One would be to modify an existing
weapon, to give it greater capability against ... hard targets and deeply-buried targets.
And we’re also looking at non-nuclear ways that we might be able to deal with those
problems.” A Washington Post article of January 10, 2002, quoted White House
Press Secretary Ari Fleischer as saying that the President has not ruled out testing
“‘to make sure the stockpile, particularly as it is reduced, is reliable and safe. So he
has not ruled out testing in the future, but there are no plans to do so.’”4
Critics expressed concern about the implications of these policies for testing and
new weapons. A statement by Physicians for Social Responsibility said, “The
Administration’s plan ... would streamline our nuclear arsenal into a war-fighting
force, seek the opportunity to design and build new nuclear weapons, and abandon
3 U.S. Department of Defense. News Transcript: “Special Briefing on the Nuclear Posture
Review,” January 9, 2002; see [http://www.defenselink.mil/transcripts/2002/t01092002_
t0109npr.html].
4 Walter Pincus, “U.S. Aims for 3,800 Nuclear Warheads,” Washington Post, January 10, 2002.

CRS-4
a ten-year-old moratorium on nuclear weapons testing.”5 Another critic felt that
increased funding for test readiness would in effect give prior approval for testing.
In July 2002 a National Academy of Sciences panel report on technical aspects
of the CTBT concluded, in the words of an press release, “that verification
capabilities for the treaty are better than generally supposed, U.S. adversaries could
not significantly advance their nuclear weapons capabilities through tests below the
threshold of detection, and the United States has the technical capabilities to maintain
confidence in the safety and reliability of its existing weapons stockpile without
periodic nuclear tests.”6
A U.N. draft document of August 5, 2005, for signature by heads of government
and heads of state at the U.N. General Assembly meeting of September 2005,
contained a provision that the signers “resolve to ... [m]aintain a moratorium on
nuclear test explosions pending the entry into force of the Comprehensive Nuclear-
Test-Ban Treaty and call upon all States to sign and ratify the Treaty.”7 John Bolton,
the U.S. Ambassador to the U.N., reportedly called for major changes to the draft; the
CTBT passage was one of many drawing his objection.8
On June 25, 2007, Secretary of State Condoleezza Rice stated:
the Administration does not support the Comprehensive Test Ban Treaty and
does not intend to seek Senate advice and consent to its ratification. There has
been no change in the Administration’s policy on this matter. By reducing the
likelihood of the need to return to underground nuclear testing, RRW [the
Reliable Replacement Warhead] makes it more likely that the United States
would be able to continue its voluntary nuclear testing moratorium. We cannot,
however, provide guarantees regarding the voluntary moratorium. We may find
at some future time that we cannot diagnose or remedy a problem in a warhead
critical the U.S. nuclear deterrent without conducting a nuclear test.9
Similarly, a Statement of Administration Policy on S. 1547, FY2008 National
Defense Authorization Act, included the following:
5 Physicians for Social Responsibility, “PSR: Bush Nuclear Weapons Plan Sets Stage for
new Bombs, Resumption of Testing; Plan Endangers National Security, Public Health,”
press release via U.S. Newswire, January 8, 2002.
6 The National Academies, “Academy Addresses Technical Issues in Nuclear Test Ban
Treaty ...,” press release, July 31, 2002. The full report, Technical Issues Related to the
Comprehensive Nuclear Test Ban Treaty,
is available at [http://www.nap.edu/catalog.php?
record_id=10471#toc].
7 U.N. General Assembly. “Revised draft outcome document of the High-level Plenary
Meeting of the General Assembly of September 2005 submitted by the President of the
General Assembly,” A/59/HLPM/CRP.1/Rev.2, advance unedited version, August 5, 2005.
8 Julian Borger, “Question Mark over the Summit,” Manila Bulletin, August 27, 2005.
9 Letter from Condoleezza Rice, Secretary of State, to Honorable Pete Domenici, United
States Senate, June 25, 2007.

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While supporting the continued voluntary moratorium on testing, the
Administration strongly opposes a provision of section 3122 that calls for the
ratification of the CTBT. It would be imprudent to tie the hands of a future
administration that may have to conduct a test of an element of an aging,
unmodernized stockpile in order to assure the reliability of the nuclear deterrent
force. Absent such a test, the United States may not be able to diagnose or
remedy a problem in a warhead critical to the Nation’s deterrent strategy.10
The U.S. presidential candidates have made statements on the CTBT. Senator
Hillary Clinton:
I will also seek Senate approval of the Comprehensive Test Ban Treaty by 2009,
the tenth anniversary of the Senate’s initial rejection of the agreement. This
would enhance the United States’ credibility when demanding that other nations
refrain from testing.11
Senator John McCain:
I believe we must also address nuclear testing. As president I will pledge to
continue America’s current moratorium on testing, but also begin a dialogue with
our allies, and with the U.S. Senate, to identify ways we can move forward to
limit testing in a verifiable manner that does not undermine the security or
viability of our nuclear deterrent. This would include taking another look at the
Comprehensive Test Ban Treaty to see what can be done to overcome the
shortcomings that prevented it from entering into force. I opposed that treaty in
1999, but said at the time I would keep an open mind about future
developments.12
Senator Barack Obama:
And we should take advantage of recent technological advances to build
bipartisan consensus behind ratification of the Comprehensive Test Ban Treaty.13
United Kingdom: The United Kingdom cannot test because it held its nuclear
tests for several decades at the Nevada Test Site and does not have its own test site.
Its last test was held in 1991. Britain and France became the first of the original five
nuclear weapon states to ratify the CTBT, depositing instruments of ratification with
the United Nations on April 6, 1998. On February 14, 2002, and February 23, 2006,
10 U.S. Executive Office of the President. Office of Management and Budget. “Statement
of Administration Policy: S. 1547 — National Defense Authorization Act for Fiscal Year
2008,” p. 7, at [http://www.whitehouse.gov/omb/legislative/sap/110-1/s1547sap-s.pdf].
11 Hillary Rodham Clinton, “Security and Opportunity for the Twenty-first Century,”
Foreign Affairs, November/December 2007, at [http://www.foreignaffairs.org/20071101
faessay86601-p0/hillary-rodham-clinton/security-and-opportunity-for-the-twenty-first-ce
ntury.html].
12 John McCain, “Remarks by John McCain on Nuclear Security,” speech as prepared for
delivery May 27, 2008, University of Denver, Denver, CO, at [http://www.johnmccain.com/
Informing/News/Speeches/Read.aspx?guid=e9c72a28-c05c-4928-ae29-51f54de08df3].
13 Barack Obama, “Renewing American Leadership,” Foreign Affairs, July/August 2007,
pp. 8-9.

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the United Kingdom conducted subcritical experiments jointly with the United States
at the Nevada Test Site.
France: On June 13, 1995, President Jacques Chirac announced that France
would conduct eight nuclear tests at its test site at Mururoa Atoll in the South Pacific,
finishing by the end of May 1996. The armed services had reportedly wanted the
tests to check existing warheads, validate a new warhead, and develop a computer
system to simulate warheads to render further testing unneeded. Many nations
criticized the decision. On August 10, 1995, France indicated it would halt all
nuclear tests once the test series was finished and favored a CTBT that would ban
“any nuclear weapon test or any other nuclear explosion.”14 France conducted six
tests from September 5, 1995, to January 27, 1996. On January 29, 1996, Chirac
announced the end to French testing. On April 6, 1998, France and Britain deposited
instruments of ratification of the CTBT with the United Nations.
Russia: Several press reports between 1996 and 1999 claimed that Russia may
have conducted low-yield nuclear tests at its Arctic test site at Novaya Zemlya; other
reports stated that U.S. reviews of the data determined that these events were
earthquakes. Several reports between 1998 and 2000 stated that Russia had
conducted “subcritical” nuclear experiments, discussed below, which the CTBT does
not bar. Russia ratified the treaty on June 30, 2000. In September 2005, Russia
reportedly stated that it intends to continue to observe the moratorium on testing until
the CTBT enters into force as long as other nuclear powers do likewise, and
expressed its hope that the nations that must ratify the treaty for it to enter into force
will do so as soon as possible.15 In November 2007, according to Itar-Tass, Russian
Foreign Minister Sergei Lavrov “confirmed Russia’s unchanging support for the
treaty as one of the key elements of the nuclear non-proliferation regime and an
effective nuclear arms limitation tool.”16
China: China did not participate in the moratorium. It conducted a nuclear test
on October 5, 1993, that many nations condemned. It countered that it had conducted
39 tests, as opposed to the 1,054 that the United States had conducted, and needed
a few more for safety and reliability. According to one report, “China will
immediately stop nuclear testing once the treaty on the complete ban of nuclear tests
takes effect, [Chinese Premier] Li Peng said.”17 It conducted other tests on June 10
and October 7, 1994, May 15 and August 17, 1995, and June 8 and July 29, 1996.
It announced that the July 1996 test would be its last, as it would begin a moratorium
on July 30, 1996. On February 29, 2000, the Chinese government submitted the
14 Craig Whitney, “France to Back Ban After Its Atom Tests,” New York Times, August 11,
1995, p. 3.
15 “Russia Intends to Continue Moratorium on Nuclear Tests,” BBC Monitoring Former
Soviet Union,
excerpt from a report by Russian News Agency ITAR-TASS, September 23,
2005.
16 “Russia Supports CTBT as Key Element of Nuclear Non-Proliferation — FM,” Itar-Tass,
November 12, 2007.
17 “Li Peng: China’s Nuclear Tests Pose No Threat,” Xinhua, October 8, 1995, in FBIS-
TAC-95-006, December 6, 1995, p. 13.

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CTBT to the National People’s Congress for ratification. In a white paper of
December 2004, China stated its support of early entry into force and, until that
happens, its commitment to the test moratorium. As of May 2008, China had not
ratified the treaty.
India: On May 11, 1998, Prime Minister Atal Behari Vajpayee announced that
India had conducted three nuclear tests. The government stated, “The tests conducted
today were with a fission device, a low yield device and a thermonuclear device....
These tests have established that India has a proven capability for a weaponised
nuclear programme.”18 It announced two more tests May 13. An academic study
concluded, based on seismic data, that India and Pakistan overstated the number and
yields of their tests. India has conducted no tests since May 1998, but questioned
whether the United States should expect India to sign a treaty that the United States
views as flawed. In an Indian-Pakistani statement of June 20, 2004, “Each side
reaffirmed its unilateral moratorium on conducting further nuclear test explosions”
barring “extraordinary events.”19 On December 22, 2005, Shri Rao Inderjit Singh,
Minister of State in the Ministry of External Affairs, said, “India has already stated
that it will not stand in the way of the Entry into Force of the Treaty.”20 On August
16, 2007, India’s External Affairs Minister, Pranab Mukherjee, reportedly told
Parliament, “India has the sovereign right to test and would do so if it is necessary
in national interest.”21 As of May 2008, India had not signed the CTBT.
A statement on U.S.-Indian nuclear cooperation of July 18, 2005, by President
Bush and Indian Prime Minister Manmohan Singh, said, “The Prime Minister
conveyed that for his part, India would reciprocally agree that it would be ready to
... continu[e] India’s unilateral moratorium on nuclear testing.”22 In a Senate hearing
of November 2, Robert Joseph, Under Secretary of State for Arms Control and
International Security, stated, “India’s pledge to maintain its nuclear testing
moratorium contributes to nonproliferation efforts by making its ending of nuclear
explosive tests one of the conditions of full civil nuclear cooperation.”23 At that
18 India. Ministry of External Affairs. Press statement, New Delhi, May 11, 1998, at [http://
nuclearweaponarchive.org/India/Indianofficial.txt].
19 India. Ministry of External Affairs. “Joint Statement, India-Pakistan Expert-Level Talks
on Nuclear CBMs [Confidence-Building Measures],” June 20, 2004.
20 India. Ministry of External Affairs. Rajya Sabha. Unstarred Question No. 3260, to be
answered on December 12, 2005, by Rao Inderjit Singh, Minister of State in the Ministry
of External Affairs. [http://164.100.24.219/rsq/quest.asp?qref=108782].
21 “Pranab Mukherjee Says India Has Sovereign Right to Conduct Nuclear Test,”
AndhraNews.net, August 16, 2007; available at [http://www.andhranews.net/India/2007/
August/16-Pranab-Mukherjee-says-11996.asp].
22 U.S. White House. “Joint Statement Between President George W. Bush and Prime
Minister Manmohan Singh,” July 18, 2005, at [http://www.whitehouse.gov/news/releases/
2005/07/20050718-6.html].
23 U.S. Congress. Senate. Committee on Foreign Relations. Hearing, Implications of U.S.-
India Nuclear Energy Cooperation
, statement by Robert Joseph, Under Secretary of State
for Arms Control and International Security, November 2, 2005. Transcript by CQ
(continued...)

CRS-8
hearing, Michael Krepon, co-founder of the Stimson Center, argued that statements
by Indian government officials that there are no current plans to test “do not carry
equal weight, nor do they impose equal responsibility, to the obligations accepted by
the 176 states that have signed the CTBT.”24 Press reports of April 2006 said the
sides were negotiating a detailed nuclear cooperation agreement. The reports
indicated that the United States would insist that India maintain its moratorium on
nuclear testing or else the United States would have the right to terminate the
agreement. India responded that it had already pledged to maintain the moratorium,
rendering this provision out of place in the final agreement. A press report of January
2007 quoted National Security Advisor M.K. Narayanan as saying, “There is no
question of signing the Comprehensive Test Ban Treaty. We have our voluntary
moratorium. That position remains.”25 According to a report of November 2007,
when some members of Parliament criticized the U.S.-Indian nuclear agreement on
grounds it would bar Indian nuclear testing, Prime Minister Manmohan Singh
responded, “If a necessity for carrying out a nuclear test arises in future, there is
nothing in the agreement which prevents us from carrying out tests.”26 (See CRS
Report RL33529, India-U.S. Relations, by K. Alan Kronstadt.)
Pakistan: Pakistan announced on May 28, 1998, that it had conducted five
nuclear tests, and announced a sixth on May 30. Reports placed the yields of the
smallest devices between zero and a few kilotons, and between 2 and 45 kilotons for
the largest. Some question the number of tests based on uncertain seismic evidence.
Pakistan made no claims of testing fusion devices. Pakistan’s weapons program
apparently relies heavily on foreign technology. Pakistan claimed that it tested
“ready-to-fire warheads,” not experimental devices, and included a warhead for the
Ghauri, a missile with a range of 900 miles, and low-yield tactical weapons. In
response to the Indian and Pakistani tests, the United States imposed economic
sanctions on the two nations. In November 1999, Foreign Minister Abdul Sattar said
that his nation would not sign the CTBT unless sanctions were lifted, but that “[w]e
will not be the first to conduct further nuclear tests.”27 In August 2000, President
Pervez Musharraf said the time was not ripe to sign the CTBT because so doing
could destabilize Pakistan.28 In September 2005, Pakistan reportedly said it would
23 (...continued)
Transcriptions, Inc.
24 U.S. Congress. Senate. Committee on Foreign Relations. Hearing, Implications of U.S.-
India Nuclear Energy Cooperation
, statement by Michael Krepon, Co-Founder, The Henry
L. Stimson Center, November 2, 2005. Transcript by CQ Transcriptions, Inc.
25 “India Not to Accept Any Legal Binding on N-Testing,” Press Trust of India Limited,
January 13, 2007.
26 “Indian Lawmakers Attack U.S. Nuclear Deal,” Global Security Newswire, November 29,
2007.
27 Kathy Gannon, “New Pakistani Government Gives First Official Foreign Policy
Statement,” newswire, Associated Press, November 8, 1999.
28 Shahid-ur-Rehman Khan, “Signing CTBT Can Destabilize Pakistan, Says Musharraf,”
newswire, Kyodo News International, Inc., August 17, 2000.

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not be the first nation in the region to resume nuclear testing.29 In April 2007,
Pakistan’s Prime Minister, Shaukat Aziz, reportedly said that Pakistan would not
unilaterally sign the CTBT since it shares a border with India.30 Replying to the
statement on nuclear testing by Pranab Mukherjee, India’s External Affairs Minister,
Tasnim Aslam, a spokeswoman for Pakistan’s Foreign Office, reportedly said, “We
take seriously the assertions by the Indian leadership about the possibility of
renewing nuclear tests.... Resumption of nuclear tests by India would create a serious
situation obliging Pakistan to review its position and to take action, appropriate,
consistent to our supreme national interest.”31 As of May 2008, Pakistan had not
signed the CTBT.
The North Korean Nuclear Test
Negotiations to halt North Korea’s nuclear program have been underway for
years, most recently between that nation, the United States, China, Japan, South
Korea, and Russia (Six-Party Talks). A CIA report of late 2004 stated that during
talks in April 2003, “North Korea privately threatened to ‘transfer’ or ‘demonstrate’
its nuclear weapons.”32 On February 10, 2005, North Korea declared, “We ... have
manufactured nukes for self-defence to cope with the Bush administration’s
evermore undisguised policy to isolate and stifle North Korea,”33 and on June 9 it
claimed it was building more such weapons. On May 15, 2005, the United States
warned that it and other nations would take punitive action if North Korea conducted
a nuclear test.34 In a joint statement from the Six-Party Talks in September 2005,
North Korea “committed to abandoning all nuclear weapons and existing nuclear
programs and returning, at an early date, to the Treaty on the Non-Proliferation of
Nuclear Weapons and to IAEA safeguards.”35 In November 2005, North Korea
began a boycott of the talks. On October 3, 2006, North Korea stated that it “will,
29 “Pakistan Today Said It Will Abide by Its ‘Solemn Pledge’ That It Would Not Be the First
Country in the Region to Resume Nuclear Tests ...,” newswire, Press Trust of India Limited,
September 26, 2005.
30 “Pak Says No to Signing NPT, CTBT Unilaterally,” Press Trust of India Limited, April
26, 2007.
31 “Pakistan Would Consider Nuclear Test If India Tests,” Reuters, August 20, 2007,
available at [http://in.reuters.com/article/topNews/idINIndia-29063920070820].
32 “Attachment A: Unclassified Report to Congress on the Acquisition of Technology
Relating to Weapons of Mass Destruction and Advanced Conventional Munitions, 1 July
Through 31 December 2003.” Note: “The Director of Central Intelligence (DCI) hereby
submits this report in response to a congressionally directed action in Section 721 of the
FY1997 Intelligence Authorization Act ...,” c. 2004, p. 5.
33 “Korean Central News Agency North Korea February 10,” The Guardian, February 12,
2005.
34 David Sanger, “U.S. in Warning to North Korea on Nuclear Test,” New York Times, May
16, 2005, p. 1.
35 “Joint Statement of the Fourth Round of the Six-Party Talks,” Beijing, September 19,
2005, at [http://www.state.gov/r/pa/prs/ps/2005/53490.htm].

CRS-10
in the future, be conducting a nuclear test.”36 In response, Japan, the United
Kingdom, and the United States warned of consequences if North Korea conducted
a test; South Korea expressed “deep regret and concern.” For updates on the Six-
Party Talks, see CRS Report RL33590, North Korea’s Nuclear Weapons
Development and Diplomacy
, by Larry A. Niksch.
On October 9, 2006, North Korea declared that it had conducted an underground
nuclear test. One report placed the yield at as little as 0.2 kilotons.37 According to
other reports, South Korean geologists placed the explosive yield at 550 tons of TNT
equivalent (0.55 kilotons),38 the French Atomic Energy Commission’s estimate was
0.50 kilotons,39 and Russian Minister of Defense Sergei Ivanov placed the yield at 5
to 15 kilotons.40 For comparison, the Hiroshima bomb had a yield of 15 kilotons.
A yield of less than a kiloton is well below the 9 or more kilotons of other nations’
first nuclear tests,41 and below the 4 kilotons that North Korea reportedly told China
that it expected.42 On October 16, the Office of the Director of National Intelligence
released a statement on the test: “Analysis of air samples collected on October 11,
2006 detected radioactive debris which confirms that North Korea conducted an
underground nuclear explosion in the vicinity of P’unggye on October 9, 2006. The
explosion yield was less than a kiloton.”43
Most U.S. observers cited in news reports believe that the event was a small
nuclear explosion, but at most a partial success. One hypothesis is that, through poor
design, the device did not implode properly, greatly reducing its yield.44 Other
hypotheses are that the device reduced the amount of plutonium used in order to
conserve that material, or engineers sought to test the design rather than yield of the
36 Democratic People’s Republic of Korea, Foreign Ministry Statement, Pyongyang Korean
Central Broadcasting Station, October 3, 2006.
37 “White House Casts Doubt on N. Korean Nuclear Arms,” Reuters newswire, October 10,
2006.
38 Evan Ramstad, Jay Solomon, and Gordon Fairclough, “Bomb Fallout: Explosion by North
Koreans Imperils Nuclear-Control Effort,” Wall Street Journal, October 10, 2006, p. 1.
39 Michael Abramowitz and Colum Lynch, “U.S. Urges Sanctions on North Korea,”
Washington Post, October 10, 2006, in graphic, “North Korea’s Big Test,” p. 13.
40 William Broad and Mark Mazzetti, “Blast May Be Only a Partial Success, Experts Say,”
New York Times, October 10, 2006, p. 8.
41 James Sterngold, “U.S. Urges Sanctions to Restrain North Korea,” San Francisco
Chronicle,
October 10, 2006, p. 1.
42 Broad and Mazzetti, “Blast May Be Only a Partial Success, Experts Say.”
43 U.S. Office of the Director of National Intelligence. Public Affairs Office. “Statement by
the Office of the Director of National Intelligence on the North Korea Nuclear Test,”
October 16, 2006, ODNI News Release No. 19-06, 1 p.
44 Dafna Linzer and Thomas Ricks, “U.S. Waits for Firm Information on Nature and Success
of Device,” Washington Post, October 11, 2006, p. 14.

CRS-11
device, or the device was smaller and more sophisticated than anticipated.45 On the
latter point, Siegfried Hecker, former Director, Los Alamos National Laboratory,
stated that the North Korean weapon designers most likely did not test a
Nagasaki-type device (a basic implosion device) because they could have had high
confidence, without testing, that such a device would work. Instead, his analysis is
that the North Koreans most likely tested a more advanced design, even at the risk
of partial failure, which is what the seismic signals appear to confirm. He considers
it highly unlikely that they intentionally designed a mini-nuke. However, even if the
test was not fully successful, he believes they learned much from the test.46
A more advanced warhead would be of greater military value to North Korea
than a Nagasaki bomb because a missile could carry it, but further tests might well
be needed to make the warhead militarily usable. The press carried reports that North
Korea said it would not conduct further tests, but according to another report,
Secretary of State Condoleezza Rice said that Chinese officials, briefing her on the
North Korean situation, said nothing about a North Korean test halt.47 It would take
some time to prepare for another test by determining the lessons of the first test,
redesigning the device, and testing components of the new design. A moratorium
during that time would have little if any impact on its test program.
The seismic record of the North Korean test, when compared with recordings
of a 2002 earthquake recorded at a seismic station in Wonju, Republic of Korea,
shows differences in seismic wave patterns that are diagnostic of an explosive
source.48 For example, seismic waves from the earthquake build up over several
seconds, while waves from the explosion arrive suddenly. Once the amplitudes are
measured, the yield may be estimated, but this is complicated by factors such as the
local geology and the specifics of the burial. Arthur Lerner-Lam, Associate Director
for Seismology, Geology, and Tectonophysics, Lamont-Doherty Earth Observatory,
Columbia University, said that the seismic record is not useful for determining
whether the event was a nuclear or conventional explosion without making additional
assumptions or inferences.49 Mining explosions are typically detonated over several
seconds in order to break rock efficiently, so their seismological signature can be
interpreted in terms of such “ripple firing.” However, if North Korea attempted to
mimic the signature of a nuclear explosion by setting off all the explosive at the same
time, Lerner-Lam said, it would be virtually impossible to discriminate between
45 Dafna Linzer, “Low Yield of Blast Surprises Analysts,” Washington Post, October 10,
2006, p. 12.
46 Personal communication, October 13, 2006.
47 Burt Herman, “U.S. Says No Sign of NKorea Promise Not to Test; SKorea’s Ex-President
Warns of Backlash,” Associated Press Newswires, October 21, 2006.
48 For the two seismographs, see “The CTBT Verification Regime Put to the Test — The
Event in the DPRK on 9 October 2006,” Comprehensive Nuclear-Test-Ban Treaty
Preparatory Commission, at [http://www.ctbto.org/press_centre/featured_articles/2007/
2007_0409_dprk.htm]. For a detailed discussion of the seismic record of the North Korean
test, see Paul Richards and Won-Young Kim, “Seismic Signature,” Nature Physics, January
2007, pp. 4-6.
49 Personal communication, October 10, 2006.

CRS-12
conventional and nuclear explosions using seismological data alone. Complementary
observations provide more direct evidence. A nuclear explosion releases radioactive
isotopes of certain gases. They may take days to reach the surface, but once they
dissipate into the atmosphere, he said, they may be detected by specially-equipped
aircraft or ground stations.50
The ability of the seismic network to detect an explosion that most sources place
at or below one kiloton, and in one case as low as one-fifth of a kiloton, may hold
implications for the CTBT. The treaty’s supporters claim that the ability to detect
subkiloton tests should negate arguments against the treaty on grounds of inadequate
monitoring capability. The Comprehensive Nuclear-Test-Ban Treaty Organization
Preparatory Commission, for example, states, “the CTBT verification regime proved
that it was capable of meeting the expectations set for it,”51 even though the test was
low yield, the IMS was 60% completed, and the noble gas system was 25%
completed.52 Critics respond that the test was not evasively conducted; that evasion
scenarios, such as testing during an earthquake or in a large underground cavity,
could defeat monitoring efforts; and that subkiloton tests could aid in developing
nuclear weapons.
The CTBT: Negotiations and Key Provisions
The Conference on Disarmament, or CD, calls itself “the sole multilateral
disarmament negotiating forum of the international community.” It is affiliated with
and funded by the United Nations, yet is autonomous from the U.N. It operates by
consensus; each member state can block a decision. On August 10, 1993, the CD
gave its Ad Hoc Committee on a Nuclear Test Ban “a mandate to negotiate a CTB.”
On November 19, 1993, the United Nations General Assembly unanimously
approved a resolution calling for negotiation of a CTBT. The CD’s 1994 session
opened in Geneva on January 25, with negotiation of a CTBT its top priority.
The priority had to do with extension of the Nuclear Non-Proliferation Treaty
(NPT).53 That treaty entered into force in 1970. It divided the world into nuclear
“haves” — the United States, Soviet Union, Britain, France, and China, the five 54
declared nuclear powers, which are also the permanent five (“P5”) members of the
50 For a technical analysis of the North Korean test, see Richard Garwin and Frank von
Hippel, “A Technical Analysis: Deconstructing North Korea’s October 9 Nuclear Test,”
Arms Control Today, November 2006.
51 “The CTBT Verification Regime Put to the Test — The Event in the DPRK on 9 October
2006.” This source also has links to many documents on the North Korean test.
52 Information provided by CTBTO PrepCom, personal communication, February 15, 2008.
53 For text of the treaty, see [http://www.state.gov/t/isn/trty/16281.htm#treaty].
54 For detailed information on the CTBT negotiations, see Jaap Ramaker, Jenifer Mackby,
Peter Marshall, and Robert Geil, The Final Test: A History of the Comprehensive Nuclear-
Test-Ban Treaty Negotiations,
Vienna, Austria, Provisional Technical Secretariat of the
Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization,
2003, 291 p.

CRS-13
U.N. Security Council — and nuclear “have-nots.” The P5 would be the only States
Party to the NPT to have nuclear weapons, but they (and others) would negotiate in
good faith on halting the nuclear arms race soon, on nuclear disarmament, and on
general and complete disarmament. Nonnuclear weapon states saw attainment of a
CTBT as the touchstone of good faith on these matters. The NPT provided for
reviews every five years; a review in 1995, 25 years after it entered into force, would
determine whether to extend the treaty indefinitely or for one or more fixed periods.
The Review and Extension Conference of April-May 1995 extended the treaty
indefinitely. Extension was accompanied by certain measures, including a Decision
on Principles and Objectives for Nuclear Non-Proliferation and Disarmament that set
forth goals on universality of the NPT, nuclear weapon free zones, etc., and stressed
the importance of completing “the negotiations on a universal and internationally and
effectively verifiable Comprehensive Nuclear-Test-Ban Treaty no later than 1996.”
The extension decision, binding on States Party to the NPT, was contentious.
Nonnuclear States Party argued that the P5 failed to meet their NPT obligations by
not concluding a CTBT. They saw progress on winding down the arms race as
inadequate. They assailed the NPT as discriminatory because it divides the world
into nuclear and nonnuclear states, and argued for a regime in which no nation has
nuclear weapons. The CTBT, in their view, symbolized this regime because, unlike
the NPT, the P5 would give up something tangible, the ability to develop new
sophisticated warheads. Some nonnuclear states saw NPT extension as their last
source of leverage for a CTBT. Other nonnuclear states felt that the NPT was in the
interests of all but would-be proliferators, that anything less than indefinite extension
would undermine the security of most nations, and that the NPT was too important
to put at risk as a means of pressuring the P5 for a CTBT. The explicit linkage
finally drawn between CTBT and NPT lent urgency to negotiations on the former.
The CD reached a draft treaty in August 1996. India argued that the CTBT
“should be securely anchored in the global disarmament context and be linked
through treaty language to the elimination of all nuclear weapons in a time bound
framework.”55 India also wanted a treaty to bar weapons research not involving
nuclear tests. The draft treaty did not meet these conditions, which the nuclear
weapon states rejected, so India vetoed it at the CD on August 20, barring it from
going to the U.N. General Assembly as a CD document. As an alternate way to open
the treaty for signing, Australia on August 23 asked the General Assembly to
consider a resolution to adopt the draft CTBT text and for the Secretary-General to
open it for signing so it could be adopted by a simple majority, or by the two-thirds
majority that India sought, avoiding the need for consensus. A potential pitfall was
that the resolution (the treaty text) was subject to amendment, yet the nuclear weapon
states viewed amendments as unacceptable. India did not raise obstacles to the vote,
which was held September 10, with 158 nations in favor, 3 against (India, Bhutan,
and Libya), 5 abstentions, and 19 not voting.
55 India. Embassy. “Statement by Ms. Arundhati Ghose, Ambassador/Permanent
Representative of India to UN, Geneva, in the Plenary of the Conference on Disarmament
on January 25, 1996,” at [http://www.indianembassy.org/policy/Disarmament/cd(jan2596)
.htm].

CRS-14
A sixth five-year NPT review conference was held April 24-May 19, 2000, in
New York. U.S. rejection of the CTBT, lack of Chinese ratification, U.S. efforts to
seek renegotiation of the ABM Treaty, and efforts to ban nuclear weapons in the
Middle East led some to fear dire outcomes from the conference. However, some
contentious issues were ironed out, some were avoided, and concessions were made.
For example, a joint statement by the P5 to the conference on May 1 said, “No efforts
should be spared to make sure that the CTBT is a universal and internationally and
effectively verifiable treaty and to secure its earliest entry into force.”56 As a result
of effort by many nations, the final document of the conference was adopted by
consensus. The document included a 13-step Nuclear Disarmament Plan of Action,
the first two elements of which called for the early entry into force of the treaty and
a moratorium on nuclear explosions pending entry into force.
At the NPT Review Conference of May 2005, the CTBT was a point of
contention. For example, Alberto Romulo, Secretary of Foreign Affairs, Republic
of the Philippines, said, “Plans to develop new nuclear weapons technology and
failure to bring the Comprehensive Test Ban Treaty (CTBT) into force seriously
erode the historic foundations of the NPT.”57 Ihor Dolhov, Deputy Foreign Minister
for Foreign Affairs of Ukraine, said, “Ukraine continues to underscore the
importance and urgency of an early entry into force of the Treaty and calls upon all
States who have not yet done so to adhere to the Treaty without delay and
unconditionally...”58 Ambassador Ronaldo Sardenberg of Brazil said, “Brazil has
consistently called for the universalization of the CTBT, which we consider to be an
essential element of the disarmament and non-proliferation regime.” 59
The balance of this section summarizes key CTBT provisions.60
56 France. Embassy of France in the United States. “2000 Review Conference of the Parties
to the Treaty on the Non-Proliferation of Nuclear Weapons: Statement by the Delegations
of France, The People’s Republic of China, The Russian Federation, The United Kingdom
of Great Britain and Northern Ireland and The United States of America,” New York, May
1, 2000, at [http://www.ambafrance-us.org/news/statmnts/2000/tnp5.asp].
57 Philippines. Mission to the United Nations. “Collective Action: Regional Responsibility
and Global Accountability Towards a World Free of Nuclear Weapons, Statement by H.E.
Dr. Alberto G. Romulo, Secretary of Foreign Affairs, Republic of the Philippines, at the
General Debate of the 2005 Review Conference of the Nuclear Non-Proliferation Treaty,
New York, 11 May 2005,” p. 2, at [http://www.un.org/events/npt2005/statements/npt11
philippines.pdf].
58 Ukraine. Permanent Mission of Ukraine to the United Nations. “Statement by H.E. Mr.
Ihor Dolhov, Deputy Minister for Foreign Affairs of Ukraine, at the 2005 NPT Review
Conference, New York, 5 May 2005,” p. 4, at [http://www.un.org/events/npt2005/
statements/npt05ukraine.pdf].
59 Brazil. “VII Review Conference of Treaty on the Non-Proliferation of Nuclear Weapons,
Statement by the Head of the Delegation of Brazil, Ambassador Ronaldo Sardenberg, New
York, 2 May 2005,” p. 4, at [http://www.un.org/events/npt2005/statements/npt04brazil.pdf].
60 For treaty text and analysis, see U.S. Congress. Senate. Comprehensive Nuclear Test-Ban
Treaty: Message from the President of the United States Transmitting Comprehensive
Nuclear Test-Ban Treaty...,
Treaty Doc. 105-28, September 23, 1997. Washington: GPO,
(continued...)

CRS-15
Scope (Article I): The heart of the treaty is the obligation “not to carry out any
nuclear weapon test explosion or any other nuclear explosion.” This formulation
bars even very low yield tests that some in the nuclear weapon states had wanted, and
bars peaceful nuclear explosions that China had wanted, but rejects India’s concern
that a CTBT should “leave no loophole for activity, either explosive based or
non-explosive based, aimed at the continued development and refinement of nuclear
weapons.”61 Views differ on whether the ban covers tests with the tiniest nuclear
yield; unless cooperative monitoring measures were used, the yield of such tests
would be below the threshold of detection.
Organization (Article II): The treaty establishes a Comprehensive Nuclear-
Test-Ban Treaty Organization (CTBTO), composed of all member states, to
implement the treaty.62 Three groups are under this Organization. The Conference
of States Parties, composed of a representative from each member state, shall meet
in annual and special sessions to consider and decide issues within the scope of the
treaty and oversee the work of the other groups. An Executive Council with 51
member States shall, among other things, take action on requests for on-site
inspection, and may request a special session of the Conference. A Technical
Secretariat shall carry out verification functions, including operating an International
Data Center (IDC), processing and reporting on data from an International
Monitoring System, and receiving and processing requests for on-site inspections.
Verification (Article IV): The treaty establishes a verification regime. It provides
for collection and dissemination of information, permits States Party to use national
technical means of verification, and specifies verification responsibilities of the
Technical Secretariat. It establishes an International Monitoring System (IMS) and
provides for on-site inspections. The treaty calls for the IMS to have, when
complete, 321 stations worldwide to monitor for signals that might indicate a nuclear
explosion: 170 seismic stations to monitor seismic waves in the Earth; 11
hydroacoustic stations to monitor underwater sound waves; 60 arrays of infrasound
detectors to monitor very low frequency sound waves in the atmosphere; and 80
radionuclide stations to detect radioactive particles and (for half the stations) gases
that a nuclear explosion might produce, as well as 16 radionuclide laboratories to
analyze radioactive samples. Of the seismic stations, 50 are to be primary stations
to provide data to IDC continuously and in real time, while 120 are to be auxiliary
stations to provide data when requested by the IDC. As of January 2008, 37 primary
seismic stations, 79 auxiliary seismic stations, 10 hydroacoustic stations, 39
infrasound arrays, 50 radionuclide stations, and 10 radionuclide laboratories had been
certified.63 That is, they are completed and meet the technical requirements of the
Preparatory Commission. They transmit data automatically and continuously to the
IDC, excepting for the auxiliary stations and the radionuclide laboratories, which
60 (...continued)
1997, xvi + 230 p, or [http://www.state.gov/t/isn/trty/16411.htm].
61 India, “Statement by Ms. Arundhati Ghose, ... January 25, 1996.”
62 For further information on the CTBTO, see its website at [http://www.ctbto.org].
63 Information provided by Comprehensive Nuclear-Test-Ban Treaty Preparatory
Commission, personal communication, February 15, 2008.

CRS-16
transmit data as requested by the IDC.64 The commission “plans to have 90% of the
IMS network installed by 2008.”65
Review of the Treaty (Article VIII): The treaty provides for a conference 10
years after entry into force (unless a majority of States Party decide not to hold such
a conference) to review the treaty’s operation and effectiveness. Further review
conferences may be held at subsequent intervals of 10 years or less.
Duration and Withdrawal (Article IX): “This treaty shall be of unlimited
duration.” However, “Each State Party shall, in exercising its national sovereignty,
have the right to withdraw from this Treaty if it decides that extraordinary events
related to the subject matter of this Treaty have jeopardized its supreme interests.”
President Clinton indicated his possible willingness to withdraw from the Treaty
using this withdrawal provision, which is common to many arms control agreements,
in his speech of August 11, 1995, discussed below, as one of several conditions under
which the United States would enter the CTBT.
Entry into force (Article XIV): The treaty shall enter into force 180 days after
44 states named in Annex 2 have deposited instruments of ratification, but not less
than two years after the treaty is opened for signature. If the treaty has not entered
into force three years after being opened for signature, and if a majority of states that
have deposited instruments of ratification so desire, a conference of these states shall
be held to decide how to accelerate ratification. Unless otherwise decided, subsequent
conferences of this type shall be held annually until entry into force occurs. The 44
states are those with nuclear reactors that participated in the work of the CD’s 1996
session and were CD members as of June 18, 1996. This formulation includes
nuclear-capable states and nuclear threshold states (in particular Israel, which, along
with other States, joined the CD on June 17, 1996), and excludes the former
Yugoslavia. Of the 44, as of May 28, 2008, India, North Korea, and Pakistan had not
signed the treaty and China, Egypt, Indonesia, Iran, Israel, and the United States had
not ratified it.
Annexes: Annex 1 lists the regional groupings of states; Annex 2 lists the 44
states that must ratify the treaty, pursuant to Article XIV, for it to enter into force.
Protocol: The Protocol provides details on the IMS and on functions of the
International Data Center (Part I); spells out on-site inspection procedures in great
detail (Part II); and provides for certain confidence-building measures (Part III).
Annex 1 to the Protocol lists International Monitoring System facilities: seismic
stations, radionuclide stations and laboratories, hydroacoustic stations, and
64 Information provided by Annika Thunborg, Chief, Public Information, Comprehensive
Nuclear-Test-Ban Treaty Preparatory Commission, personal communication, November 26,
2007.
65 Comprehensive Test Ban Treaty Preparatory Commission, “Number of Certified IMS
Facilities Passes 200 Mark,” press release PI/2007/03, March 29, 2007, available at
[http://www.ctbto.org/press_centre/press_release.dhtml?item=292]. The Comprehensive
Nuclear-Test-Ban Treaty Preparatory Commission reaffirmed the 90-percent figure in
February 2008.

CRS-17
infrasound stations. Annex 2 provides a list of variables that, among others, may be
used in analyzing data from these stations to screen for possible explosions.
Preparing for Entry into Force
States that had signed the CTBT established the Preparatory Commission
(PrepCom) for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO)
to prepare for entry into force of the treaty, such as by creating the structures and
instruments of the CTBT. The PrepCom states that its main task “is to establish the
global verification regime foreseen in the Treaty so that it will be operational by the
time the Treaty enters into force.” The PrepCom held 29 meetings from November
1996 through November 2007. The next is scheduled for June 23-26, 2008. Eleven
meetings of working groups and advisory groups are scheduled for 2008. The
PrepCom also holds training sessions, workshops, etc.66
The United Nations conducted entry-into-force conferences under Article XIV in
October 1999, November 2001, September 2003, September 2005, and September 2007.
The final declaration of the 2007 conference called on all states to sign and ratify the
treaty “without delay,” especially those states required for entry into force, and adopted
11 measures to promote entry into force.67 The Comprehensive Nuclear-Test-Ban Treaty
Organization Preparatory Commission served as the secretariat of these conferences.
There have been other calls for entry into force. In September 2002, a statement
by 18 foreign ministers, including those of Britain, France, and Russia, called for early
entry into force. On November 22, 2002, the U.N. General Assembly adopted resolution
57/100 (164 for, 1 against (U.S.A.), 5 abstentions) urging states to maintain their nuclear
test moratoria and urging states that had not signed and ratified the CTBT to do so as
soon as possible and to avoid actions that would defeat its object and purpose. In a
message to the 2003 conference, U.N. Secretary-General Kofi Annan urged the nations
that had to ratify the treaty for it to enter into force, and especially North Korea, to ratify,
and urged continuing the moratorium: “No nuclear testing must be tolerated under any
circumstances.”68 A conference of the Non-Aligned Movement, which has 116
members, ended on February 25, 2003. Its Final Document stated that the heads of state
or government “stressed the significance of achieving universal adherence to the
Comprehensive Nuclear-Test-Ban Treaty (CTBT), including by all the Nuclear Weapons
66 For information on PrepCom and other meetings, see [http://www.ctbto.org]. For a
complete calendar for 2007, see [http://www.ctbto.org/prepcom/calendar2007.pdf].
67 Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization,
“Ratifiers and States Signatories Urge Outstanding States to Sign and Ratify the
Comprehensive Nuclear-Test-Ban Treaty,” press release, September 18, 2007, available at
[http://www.ctbto.org/].
68 U.N. “No Nuclear Testing Must Be Tolerated under Any Circumstances.” Press Release
SG/SM/8843, DC/2885, September 3, 2003, at [http://www.un.org/News/Press/docs/2003/
sgsm8843.doc.htm].

CRS-18
States.”69 On September 23, 2004, foreign ministers from 42 nations called for prompt
ratification of the CTBT, especially by nations whose ratification is required for entry
into force.70 A report by the Weapons of Mass Destruction Commission, an
international commission organized by Sweden, issued a report in June 2006 that,
among other things, urged all states that have not done so to sign and ratify the CTBT
“unconditionally and without delay.” It recommended that the 2007 conference of
CTBT signatories “should address the possibility of a provisional entry into force of
the treaty.” It stated, “The Commission believes that a U.S. decision to ratify the
CTBT would strongly influence other countries to follow suit. It would decisively
improve the chances for entry into force of the treaty and would have more positive
ramifications for arms control and disarmament than any other single measure.”71 In
September 2006, to mark the tenth anniversary of the CTBT’s opening for signature,
59 foreign ministers issued a joint statement on the treaty that “[calls] upon all States
that have not yet done so to sign and ratify the Treaty without delay, in particular
those whose ratification is needed for its entry into force.”72
In January 2007, George Shultz, William Perry, Henry Kissinger, and Sam Nunn
urged the United 73States to work toward a world without nuclear weapons, with one
step “Initiating a bipartisan process with the Senate, including understandings to
increase confidence and provide for periodic review, to achieve ratification of the
Comprehensive Test Ban Treaty, taking advantage of recent technical advances, and
working to secure ratification by other key states.”74 In response, a few weeks later,
Mikhail Gorbachev called on nuclear weapon states to ratify the CTBT, among other
actions.75 On November 19, former Secretary of Defense Harold Brown and former
Director of Central Intelligence John Deutch suggested a five-year renewable CTBT
69 Non-Aligned Movement, Kuala Lumpur Summit, February 20-25, 2003, “Non-Aligned
Movement Conference Stresses Importance of CTBT,” at [http://pws.ctbto.org/press_centre/
featured_articles/250203_nam.html].
70 Japan. Ministry of Foreign Affairs. “Joint Ministerial Statement on the CTBT,” New
York, September 23, 2004, [http://www.mofa.go.jp/policy/un/disarmament/ctbt/joint0409.
html].
71 Weapons of Mass Destruction Commission, Weapons of Terror: Freeing the World of
Nuclear, Biological and Chemical Arms.
June 2006, p. 107, 108, at [http://www.
wmdcommission.org/files/Weapons_of_Terror.pdf].
72 “Joint Ministerial Statement on the CTBT,” New York, September 20, 2006, at
[http://www.armscontrol.org/pdf/20060920_CTBT_Joint_Ministerial_Statement.pdf#sea
rch=%22%20%22joint%20ministerial%20statement%20on%20the%20ctbt%22%22].
73 Testimony of Siegfried Hecker, former Director, Los Alamos National Laboratory, in U.S.
Congress. Senate. Committee on Appropriations. Subcommittee on Energy and Water
Development. Hearing on the Department of Energy and the U.S. Nuclear Weapon Non-
Proliferation Efforts, 110th Congress, 2nd Session, April 30, 2008. Transcript by CQ
Transcriptions.
74 George Shultz, William Perry, Henry Kissinger, and Sam Nunn, “A World Free of
Nuclear Weapons,” Wall Street Journal, January 4, 2007, p. 15.
75 Mikhail Gorbachev, “The Nuclear Threat,” Wall Street Journal, January 31, 2007, p. 13.

CRS-19
in lieu of the current treaty.76 In January 2008, Shultz, Perry, Kissinger, and Nunn
renewed their call for, among other things, “a process for bringing the [CTBT] into
effect” and called IMS “an effort the U.S. should urgently support even prior to
[CTBT] ratification.”77 In Senate testimony of April 2008, Siegfried Hecker, former
Director of Los Alamos National Laboratory, stated that without nuclear tests,
“slowly our confidence [in U.S. nuclear weapons] zeroes,” but that resumed U.S.
testing runs the risk that other nations would resume testing. “And as I personally
today weigh those risks, I definitely come out in favor that it’s in our nation’s and the
world’s interest to actually ratify the Comprehensive Test Ban Treaty.”
The first Preparatory Committee meeting for the 2010 NPT Review Conference
was held in Vienna, Austria, in April and May 2007. The chair of the committee
released a paper that stated, “Strong support was expressed for the CTBT. The
importance and urgency of its early entry into force was underscored. States which
had not ratified the Treaty, especially those remaining 10 States whose ratification
was necessary for its entry into force, were urged to do so without delay and without
conditions.”78 A representative of Germany, speaking on behalf of the European
Union, said, “The EU reiterates its call on States, particularly those listed in Annex
II, to sign and ratify the said Treaty without delay and without conditions and,
pending its entry into force to abide by a moratorium on nuclear testing and to refrain
from any action contrary to the obligations and provisions of the CTBT.”79 The
second Preparatory Committee meeting was held in Geneva in April and May 2008.
At the meeting, several dozen states made statements in support of the CTBT and its
entry into force.80
U.S. funding for the PrepCom is: FY2002 actual, $16.6 million; FY2003 actual,
$18.2 million; FY2004 actual, $18.9 million; FY2005 actual, $18.8 million; FY2006
actual, $14.2 million; FY2007 actual, $13.5 million; FY2008 requested, $18.0
million; FY2008 appropriated, $23.8 million (net of an across-the-board cut in the
Consolidated Appropriations Act); and FY2009 requested, $9.9 million. These funds
are in the International Affairs budget under Nonproliferation, Antiterrorism,
Demining, and Related Programs. The FY2007 budget justification stated that these
76 Harold Brown and John Deutch, “The Nuclear Disarmament Fantasy,” Wall Street
Journal,
November 19, 2007, p. 19.
77 George Shultz, William Perry, Henry Kissinger, and Sam Nunn, “Toward a Nuclear-Free
World,” Wall Street Journal, January 16, 2008, p. 13.
78 “2007 NPT PrepCom Chair’s factual summary (now to be called a Chair’s Paper),” May
11, 2007, available at [http://www.acronym.org.uk/npt/chair.pdf].
79 “First session of the Preparatory Committee for the 2010 Review Conference of the
Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, General Debate,
Statement by Ambassador Rudiger Ludeking, Deputy Commissioner of the Federal
Government [of Germany] for Arms Control and Disarmament on behalf of the European
Union,” Vienna, April 30, 2007 p. 5, available at [http://www.reachingcriticalwill.org/legal/
npt/prepcom07/statements/30aprilEU.pdf].
80 Reaching Critical Will, “Government Statements from the second session of the
Preparatory Committee for the 2010 nuclear Non-Proliferation Treaty Review Conference
28 April - 9 May 2008,” at [http://www.reachingcriticalwill.org/legal/npt/prepcom08/
statements.html].

CRS-20
funds “pay the U.S. share for the ongoing development and implementation of the
International Monitoring System (IMS), which supplements U.S. capabilities to
detect nuclear explosions. Since the United States does not seek ratification and
entry-into-force of the CTBT, none of the funds will support Preparatory
Commission activities that are not related to the IMS.”81
In March 2008, the PrepCom’s Provisional Technical Secretariat launched the
International Scientific Studies project. According to the PrepCom, the objective of
the project “is to carry out scientific studies and assessments to address and evaluate
the readiness and capability of the CTBT verification regime in a coordinated
international effort. The studies will highlight progress made in seismology,
hydroacoustics, infrasound and radionuclides monitoring.”82
Suspension of U.S. Voting Rights in the Preparatory Commission.
U.S. voting rights in the CTBTO Preparatory Commission (PrepCom) were
suspended in 2007 because of a shortfall in U.S. “assessed contributions” (i.e., dues).
They were restored on October 1, 2007, when the PrepCom received an additional
U.S. payment. The United States again lost its voting rights on January 1, 2008, but
restored them with a payment on February 25. This section explains the basis for the
suspensions, possible consequences, and the restoration of voting rights.
Article II of the treaty deals with the CTBTO. Section 11 provides,
A member of the Organization which is in arrears in the payment of its assessed
contribution to the Organization shall have no vote in the Organization if the
amount of its arrears equals or exceeds the amount of the contribution due from
it for the preceding two full years. The Conference of the States Parties may,
nevertheless, permit such a member to vote if it is satisfied that the failure to pay
is due to conditions beyond the control of the member.
However, since the CTBT has not entered into force, the CTBTO has not come
into existence. Instead, there is a PrepCom for the CTBTO. The annex to the
resolution establishing the PrepCom states:
A State Signatory which has not discharged in full its financial obligations to the
Commission within 365 days of receipt of the request for payment shall have no
vote in the Commission, until such payment is received. The Commission may,
nevertheless, permit such a member to vote if it is satisfied that the failure to pay
is due to conditions beyond the control of the member.83
81 U.S. [no agency listed]. Summary and Highlights, International Affairs Function 150,
Fiscal Year 2007 Budget Request,
p. 40, at [http://www.state.gov/documents/organization/
60297.pdf].
82 Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization,
“Want to Join a Global Scientific Project? International Scientific Studies to Evaluate the
CTBT Verification Regime,” c. April 2008, at [http://www.ctbto.org/reference/outreach/
100408_issleaflet_web.pdf].
83 Comprehensive Nuclear Test-ban Treaty. Meeting of States Signatories. Resolution
establishing the Preparatory Commission for the Comprehensive Nuclear Test-Ban Treaty
(continued...)

CRS-21
While the treaty and the resolution form the legal basis for the operation of the
PrepCom, the resolution governs decisions on voting rights.
The PrepCom’s budget is presented in dollars plus euros. Its 2007 budget was
$48.277 million plus 48.564 million, or $114.622 million as of May 2007.84 (The
PrepCom uses the calendar year as its fiscal year.) The U.S. assessment is 22.3
percent of the total, or $23.411 million, net of adjustments.85 In addition to this sum,
the United States had an arrearage of $14.912 million for prior years as of May 2007,
for a total outstanding net amount payable of $38.323 million.86 For comparison,
U.S. funding for the IMS was $14.207 million for FY2006 and $10.0 million for
FY2007; the FY2008 request was $18.0 million.87
U.S. voting rights in the PrepCom have been suspended each year beginning in
2003 because the United States did not pay its 2002 dues in full by December 31,
2002. These suspensions have lasted for a few months between the end of a calendar
year and the date when the United States paid its contribution for that year. Because
the United States has contributed less than the amount assessed for 2002 and each
subsequent year, it paid fully the previous year’s balance but contributed lesser
amounts to the current year’s assessment, so the arrearage has grown.
The arrearage results from U.S. policy. Since the United States does not seek
entry into force of the CTBT but favors improving means of monitoring nuclear
testing, the Administration requests only those funds for the PrepCom that directly
support the IMS. These funds are in the International Affairs Function 150 budget
in the Nonproliferation, Antiterrorism, Demining, and Related Programs (NADR)
account. The FY2007 budget justification, for example, stated that the requested
funds, $19.8 million, would “pay the U.S. share for the ongoing development and
implementation of the International Monitoring System (IMS), which supplements
U.S. capabilities to detect nuclear explosions. Since the United States does not seek
83 (...continued)
Organization. Adopted November 19, 1996. CTBT/MSS/RES/1, October 17, 1996. Annex:
Text on the Establishment of a Preparatory Commission for the Comprehensive Nuclear
Test-Ban Treaty Organization, Section 5(b), p. 2. Available at [http://www.ctbto.org/
reference/legal_resources/prepcom_resolution.pdf].
84 Of these amounts, $47.077 million and 48.564 million are financed by contributions
from states that have signed the treaty. The Preparatory Commission uses the U.N.
operational exchange rate for May 2007 of $1 = 0.732 (approximately 1 = $1.3661).
85 Information provided by Preparatory Commission for the CTBTO, personal
communication, May 22, 2007. The adjustments are $292,384 as the U.S. share of a cash
surplus, and an assessment reduction of $1,592,000 for services related to a seismic station
in South Korea and a radionuclide station in Antarctica.
86 Ibid.
87 FY2006 and FY2008 data are from U.S. [no agency listed]. Congressional Budget
Justification: Foreign Operations, Fiscal Year 2008,
p. 90, at [http://www.state.gov/
documents/organization/84462.pdf]. FY2007 data provided by Comprehensive Nuclear-
Test-Ban Treaty Preparatory Commission, personal communication, June 5, 2007.

CRS-22
ratification and entry-into-force of the CTBT, none of the funds will support
Preparatory Commission activities that are not related to the IMS.”88
On June 4, 2007, the United States made a payment of $10.0 million, labeled
“International Monitoring System for FY2007,” to the CTBTO PrepCom.89 This was
less than the $14.207 million provided for IMS for FY2006, and not enough to
restore U.S. voting rights. When asked why the IMS payment was less than the
FY2006 level, as might have been expected under a continuing resolution, a State
Department staff member indicated that there were other priorities within the NADR
account.90 However, on September 16, 2007, the United States paid the PrepCom
another $3.5 million, enough to restore its voting rights for calendar 2007.91
In action on H.R. 2764, FY2008 Department of State, Foreign Operations, and
Related Programs Appropriations Bill, the Senate Appropriations Committee
recommended $28.0 million for IMS vs. $18.0 million requested, and the House
passed H.R. 2764, with $10.0 million for IMS. The final version of H.R. 2764
became the FY2008 Consolidated Appropriations Act, P.L. 110-161; it included
$23.8 million for IMS.
The PrepCom states that all its actions so far have been taken by consensus
rather than by votes, and that the PrepCom has its first meeting of each year in June,92
so the immediate consequences of the United States not having a vote are limited.
CTBT supporters, though, see consequences for the IMS. That system represents a
major investment: as of December 2007, $274.9 million had been spent out of a total
estimated investment cost of $328 million.93 (The annual cost to operate IMS, the
International Data Center, and the Global Communications Infrastructure is over $70
million, or nearly 70% of the total CTBTO PrepCom budget.94) Its capacity for
monitoring nuclear tests is of use to the United States as well as to other nations.
Treaty supporters state that the United States gains the full benefit of the IMS but
pays only a fifth of its cost. They note that IMS operates in conjunction with other
monitoring systems. This combined system, in their view, is capable of detecting
very low yield nuclear tests and defeating many evasion attempts.95 They maintain
88 U.S. [no agency listed]. Summary and Highlights: International Affairs Function 150,
Fiscal Year 2007 Budget Request,
p. 40, at [http://www.state.gov/documents/organization/
60297.pdf].
89 Information provided by CTBTO PrepCom, personal communication, June 5 and 6, 2007.
90 Personal communication, June 1, 2007.
91 Information provided by CTBTO PrepCom, personal communication, February 15, 2008.
92 Information provided by CTBTO PrepCom, personal communication, May 16 and 22,
2007.
93 Information provided by CTBTO PrepCom, personal communication, February 15, 2008.
94 Information provided by CTBTO PrepCom, personal communication, March 4, 2008.
95 See, for example, National Academy of Sciences, Committee on Technical Issues Related
to Ratification of the Comprehensive Nuclear Test Ban Treaty, Technical Issues Related to
the Comprehensive Nuclear Test Ban Treaty,
Washington, National Academy Press, 2002,
(continued...)

CRS-23
that the ability of the IMS, along with other networks, to detect the North Korean
nuclear test of October 2006 argues for accelerating IMS deployment, yet the
shortfall in dues precludes such acceleration. Indeed, the PrepCom states that the
shortfall makes it difficult to build additional stations and to fund operation and
maintenance of existing IMS stations adequately..96 Daryl Kimball, Executive
Director of the Arms Control Association, said, “the U.S. failure to pay its share will
hinder the CTBTO’s ability to complete construction and certify for use the
remaining stations of the International Monitoring System. Many of these remaining
stations are to be built in remote and/or strategic areas, such as Turkmenistan, which
borders Iran.”97 While many other nations are in arrears in their dues, U.S. dues far
exceed those of any other nation that has its voting rights suspended, so its shortfall
will have a correspondingly greater impact. For example, a statement by the Group
of 77 plus China noted “the non-payment by a major contributor of its financial
obligations to the PrepCom. The Group is very concerned that during the recent
years nearly $15 million has not been paid by a major contributor. Such a situation,
if it continues, would create a serious challenge to the CTBT verification regime and
jeopardize the future of the whole system.”98 Supporters also express concern over
potential political consequences. In this view, U.S. failure to meet its obligations
weakens the incentive for other nations to pay their dues to the PrepCom, and
undercuts support for other international organizations more generally.
Opponents of the CTBT see little value in being able to cast a vote in an
organization that operates by consensus and that would implement a treaty the United
States opposes. They feel that adverse consequences to U.S. security of ratifying the
CTBT and having it enter into force outweigh immeasurably whatever beneficial
consequences might accrue from having the right to vote in the PrepCom. They note
that 87 nations had their voting rights in the PrepCom suspended as of May 16, 2007,
because of failure to pay dues,99 so the U.S. arrearage is far from unique. According
to one report, “Most political appointees working on the issue appear unperturbed by
95 (...continued)
especially Chapter 2, “CTBT Monitoring Capability,” pp. 35-59; and Paul Richards and
Won-Young Kim, “Seismic Signature,” Nature Physics, January 2007, pp. 4-6.
96 Information provided by Preparatory Commission for the CTBTO, personal
communications, May 17, 2007, and February 15, 2008.
97 “Congress Must Remedy Past U.S. Funding Shortfalls for Global Nuclear Test Monitoring
System,” media advisory, Arms Control Association, May 21, 2007.
98 “Statement by the Group of 77 and China Before the Joint Meeting of WGA [Working
Group A] and WGB of the Preparatory Commission for the CTBTO, Delivered by H.E.
Ambassador Sayed Galal E. Elamin, Permanent Representative of Sudan,” CTBT/WGB-29,
WGB-31/SD/1, May 23, 2007, pp. 2-3. The Group of 77 is a group of 130 nations
(originally 77) and is, in its words, “the largest intergovernmental organization of
developing states in the United Nations.” Group of 77, “About the Group of 77,” available
at [http://www.g77.org/doc/].
99 Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty. Table showing
2007 assessed contributions to the Preparatory Commission for the CTBTO, contributions
payable after adjustments, payments in 2007, and 2007 outstanding balance, all as of May
8, 2007, 6 p. Available at [http://www.ctbto.org/prepcom/0507_collections.pdf].

CRS-24
the voting rights suspension and the Vienna group’s [i.e., the PrepCom’s] future.”100
Opponents question the value of IMS on two grounds. First, they point to several
scenarios for clandestine testing, such as decoupling101 or conducting a test in a
remote ocean area in a way that hides the identity of the testing nation. Second, since
IMS data is available to all states party to the treaty, it would be available to states
party seeking to test clandestinely as well as to states party seeking to detect such
testing. In this view, detailed access to the data would show evaders weaknesses of
the monitoring systems, enhancing the effectiveness of evasion techniques.
With payments for the prior year due each January 1, U.S. voting rights for
calendar year 2008 were suspended on January 1, 2008. The CTBTO PrepCom
stated that the United States would need to pay $23.8 million to restore its 2008
voting rights.102 The FY2008 Consolidated Appropriations Act provided that amount
for IMS, and the United States paid the PrepCom that amount on February 25.103 As
of May 15, 2008, the U.S. arrearage was $12.1 million plus 9.7 million.104
The Administration’s FY2009 request for “CTBT International Monitoring
System” is $9.9 million.105 If this amount is appropriated, the United States would
lose its voting rights in 2009. According to the CTBTO PrepCom,
If the United States pays $24 million in calendar year 2008, it still owes the
CTBTO PrepCom almost as much in past arrears as its assessed contributions
(i.e., dues), which are about $24 million per year. In practice, if the United
States owes more than its annual assessed contributions, it will lose its voting
rights. Since it is now so deeply in arrears at the CTBTO PrepCom, it will need
to pay at least its assessed contributions each calendar year in 2009 and beyond
in order to retain its voting rights.106
100 Nicholas Kralev, “Unpaid U.S. Dues Hit Nuke-Test Monitoring,” Washington Times,
May 24, 2007, p. 13.
101 “Decoupling” is an evasion technique first proposed around 1959 in which a nuclear
explosion is conducted in a large underground cavity, thereby lowering the seismic signature
resulting from the explosion.
102 Personal communication, February 6, 2008.
103 Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization,
“The United States Pays US$ 23.8 Million to the CTBTO,” press release, February 26,
2008.
104 Arrearage figures are from a CTBTO PrepCom table of contributions and outstanding
balances, at [http://www.ctbto.org/prepcom/0507_collections.pdf], updated May 15, 2008,
p. 6. This table is updated from time to time.
105 U.S. [no agency listed]. Summary and Highlights, International Affairs Function 150,
Fiscal Year 2009 Budget Request,
p. 82, at [http://www.state.gov/documents/organization/
100014.pdf].
106 Personal communication, February 6, 2008.

CRS-25
Stockpile Stewardship
P5 states want to maintain their nuclear warheads under a CTBT and assert that
they need computers and scientific facilities to do so. They also want to retain the
ability to resume testing if other nations leave a CTBT, or if maintaining high
confidence in key weapons requires testing. Nonnuclear nations fear that the P5 will
continue to design new warheads under a CTBT, with computation and nonnuclear
experiments replacing testing. Maintaining nuclear weapons, especially without
testing, is termed “stockpile stewardship.” This is a contentious issue. This section
focuses on the U.S. debate.
Stewardship bears on Senate advice and consent to CTBT ratification.
Beginning with the Nuclear Test Ban Treaty of 1963, the United States has
implemented “safeguards,” or unilateral steps to maintain its nuclear weapons
capability consistent with treaty limitations. President Kennedy’s agreement to
safeguards was critical for obtaining Senate approval of the 1963 treaty. The
safeguards were modified most recently by President Clinton. In his August 11,
1995, speech announcing a zero-yield CTBT as a goal, he stated:
As a central part of this decision, I am establishing concrete, specific safeguards
that define the conditions under which the United States will enter into a
comprehensive test ban. These safeguards will strengthen our commitments in
the areas of intelligence, monitoring and verification, stockpile stewardship,
maintenance of our nuclear laboratories, and test readiness.107
These safeguards are: Safeguard A: “conduct of a Science Based Stockpile
Stewardship program to insure a high level of confidence in the safety and reliability
of nuclear weapons in the active stockpile”; Safeguard B: “maintenance of modern
nuclear laboratory facilities and programs”; Safeguard C: “maintenance of the basic
capability to resume nuclear test activities prohibited by the CTBT”; Safeguard D:
“a comprehensive research and development program to improve our treaty
monitoring”; Safeguard E: intelligence programs for “information on worldwide
nuclear arsenals, nuclear weapons development programs, and related nuclear
programs”; and Safeguard F: the understanding that if the Secretaries of Defense and
Energy inform the President “that a high level of confidence in the safety or
reliability of a nuclear weapon type which the two Secretaries consider to be critical
to our nuclear deterrent could no longer be certified, the President, in consultation
with Congress, would be prepared to withdraw from the CTBT under the standard
‘supreme national interests’ clause in order to conduct whatever testing might be
required.”108
107 President William J. Clinton, “Remarks Announcing a Comprehensive Nuclear Weapons
Test Ban,” August 11, 1995, in U.S. National Archives and Records Administration. Office
of the Federal Register. Weekly Compilation of Presidential Documents, August 14, 1995,
p. 1432.
108 U.S. White House. Office of the Press Secretary. “Fact Sheet: Comprehensive Test Ban
Treaty Safeguards,” August 11, 1995, 1 p.

CRS-26
Regarding the stewardship program, President Clinton said that the Secretary
of Energy and the directors of the nuclear weapons laboratories had assured him that
the United States could maintain its nuclear deterrent under a CTBT through a
science-based stockpile stewardship program. “In order for this program to succeed,”
he said, “both the administration and the Congress must provide sustained bipartisan
support for the stockpile stewardship program over the next decade and beyond.”109
The ability of the stewardship program to maintain nuclear weapons without
testing was a crucial issue in the Senate debate on the CTBT. The treaty’s opponents
claimed that stewardship offered no guarantee of maintaining weapons, and that
experiments, computer models, and other techniques might offer no clue to some
problems that develop over time. They further argued that it could be perhaps a
decade before the tools for the program were fully in place, and by that time many
weapon designers with test experience would have retired. Supporters held that the
program was highly likely to work, having already certified the stockpile three times,
and that safeguard “F” provided for U.S. withdrawal from the treaty in the event high
confidence in a key weapon type could not be maintained without testing. By March
2005, DOD and DOE had completed the ninth stockpile certification.
The ability of the stewardship program to maintain nuclear weapons without
testing is also at issue in the Reliable Replacement Warhead (RRW) program.
Initiated in the FY2005 Consolidated Appropriations Act (P.L. 108-447), the
program is developing a new warhead to replace W76 warheads currently used on
Trident II submarine-launched ballistic missiles. Congress imposed many goals for
RRW, some in legislation and some in committee reports. The FY2006 National
Defense Authorization Act, P.L. 109-163, Section 3111, set as one objective for the
program “To further reduce the likelihood of the resumption of underground nuclear
weapons testing.” Most Democrats on the House Armed Services Committee signed
a statement of additional views in the committee’s FY2006 report on defense
authorizations that included seven goals on RRW, including:
Democrats are willing to explore the concept of the RRW program but do not yet
embrace it. In our opinion, the RRW program is only worthy of support if it:
! Truly reduces or eliminates altogether the need for nuclear testing...
! Leads to ratification and entry into force of the Comprehensive Test
Ban Treaty.110
A concern expressed by RRW proponents is that current warheads, maintained
through the Life Extension Program (a part of the stockpile stewardship program),
would accumulate a series of small changes that, over time, could move warheads
109 President William J. Clinton, “Statement on a Comprehensive Nuclear Weapons Test
Ban,” August 11, 1995, in U.S. National Archives and Records Administration. Office of
the Federal Register. Weekly Compilation of Presidential Documents, August 14, 1995, p.
1433.
110 U.S. Congress. House. Committee on Armed Services. National Defense Authorization
Act for Fiscal Year 2006,
H.Rept. 109-89 on H.R. 1815, 109th Congress, 1st Session, 2005,
p. 512.

CRS-27
away from their original specifications, thereby reducing confidence in warhead
safety and reliability and making nuclear testing more likely. Critics of RRW
respond that changes can be carefully managed and that political and military leaders
are likely to raise questions about RRWs because they would be untested, and may
demand nuclear tests to resolve the matter. On March 2, 2007, the National Nuclear
Security Administration (NNSA) selected the design by Lawrence Livermore
National Laboratory and Sandia National Laboratories’ Livermore branch as the
winner in a design competition.111 (See CRS Report RL33748, Nuclear Warheads:
The Reliable Replacement Warhead Program and the Life Extension Program,
and
CRS Report RL32929, The Reliable Replacement Warhead Program: Background
and Current Developments
, both by Jonathan Medalia.)
A report of July 2007 by the Secretaries of Energy, State, and Defense linked
RRW with nuclear testing: “Delays on RRW also raise the prospect of having to
return to underground nuclear testing to certify existing weapons.”112 Commenting
on that statement, Representatives Hobson and Visclosky stated, “It is irresponsible
for the Administration to make such an assertion.... There is no record of
congressional testimony or reports sent to Congress by the Administration claiming
that the safety, security, or reliability of the existing legacy stockpile is on a
performance cliff such that a resumption of testing to verify performance of the
warheads would be a necessity.”113 Representatives Skelton and Tauscher wrote, “it
is too early to know whether RRW can deliver on the objectives that have been
established for the program.”114
In early 2007, several current and former Members of Congress discussed
linking CTBT and RRW.115 Since then, RRW’s support in Congress has diminished;
111 U.S. Department of Energy. National Nuclear Security Administration. “Design Selected
for Reliable Replacement Warhead,” press release, March 2, 2007.
112 U.S. Secretary of Energy, Secretary of Defense, and Secretary of State. “National
Security and Nuclear Weapons: Maintaining Deterrence in the 21st Century.” July 2007, p.
4.
113 Letter from Representative David Hobson, Ranking Minority Member, and
Representative Peter J. Visclosky, Chairman, Subcommittee on Energy and Water
Development, House Appropriations Committee, to The Honorable Robert Gates, Secretary
of Defense, The Honorable Condoleezza Rice, Secretary of State, and The Honorable
Samuel Bodman, Secretary of Energy, August 1, 2007.
114 Letter from Representative Ike Skelton, Chairman, House Armed Services Committee,
and Representative Ellen Tauscher, Chairman, Subcommittee on Strategic Forces, House
Armed Services Committee, to Secretary Samuel W. Bodman, Department of Energy,
Secretary Robert M. Gates, Department of Defense, and Secretary Condoleezza Rice,
Department of State, July 26, 2007.
115 See, for example, Walter Pincus, “Congress Skeptical of Warhead Plan,” Washington
Post,
April 22, 2007, p. 5; letters from Senator Pete Domenici to Dr. Robert M. Gates,
Secretary of Defense, Stephen J. Hadley, National Security Advisor, and Dr. Condoleezza
Rice, Secretary of State, April 17, 2007, available at [http://www.abqjournal.com/abqnews/
index.php?option=com_content&task=view&id=3267&Itemid=31]; Keith Costa, “Tauscher:
Time to Make CTBT Ratification a Top National Security Goal,” Inside the Pentagon,
(continued...)

CRS-28
see CRS Report RL32929, The Reliable Replacement Warhead Program:
Background and Current Developments
, for details.
Congress established NNSA in 1999 as a semiautonomous DOE agency to
manage stewardship and related programs. In NNSA’s budget, stewardship is funded
by the Weapons Activities account, the main elements of which are Directed
Stockpile Work, activities directly supporting weapons in the stockpile; Campaigns,
technical efforts to develop and maintain capabilities to certify the stockpile for the
long term; and Readiness in Technical Base and Facilities, mainly infrastructure and
operations for the weapons complex. Appropriations were: FY2001, $5.006 billion;
FY2002, $5.429 billion; FY2003, $5.954 billion; FY2004, $6.447 billion; FY2005,
$6.626 billion; and FY2006, $6.370 billion. The FY2007 operating plan contains
$6.276 billion.116 The FY2008 appropriation was $6.297 billion; the FY2009 request
is $6.618 billion.117 (See CRS Report RL34009, Energy and Water Development:
FY2008 Appropriations
, coordinated by Carl Behrens.)
The conference version of H.R. 1585, the FY2008 defense authorization bill,
removed from the Senate version a sense of Congress provision that the Senate
should ratify the CTBT and replaced it with a provision that the United States should
sustain the stockpile stewardship program (section 3126).
Subcritical experiments (SCEs): As part of the stockpile stewardship program,
NNSA is conducting SCEs. CRS offers the following definition based on documents
and on discussions with DOE and laboratory staff: “Subcritical experiments at
Nevada Test Site involve chemical high explosives and fissile materials in
configurations and quantities such that no self-sustaining nuclear fission chain
reaction can result. In these experiments, the chemical high explosives are used to
generate high pressures that are applied to the fissile materials.” The only fissile
material that has been used in SCEs is plutonium. All SCEs to date have been
conducted in a tunnel complex, about 1,000 feet underground at Nevada Test Site.
The complex could contain explosions up to 500 pounds of explosive and associated
plutonium. Another SCE, “Unicorn,” was conducted in a “down-hole” or vertical
shaft configuration similar to an underground nuclear test, not in a tunnel, to exercise
operational readiness.118 SCEs try to determine if radioactive decay of aged
plutonium would degrade weapon performance. Several SCEs have been used to
support certification of the W88 pit. (A pit is the “trigger” of a thermonuclear
115 (...continued)
February 1, 2007; and U.S. Congress. House. Committee on Appropriations. Subcommittee
on Energy and Water Development. Hearing on nuclear weapon activities, March 29, 2007,
testimony of former Senator Sam Nunn.
116 U.S. Department of Energy. FY 2007 Operating Plan by Appropriation. March 16, 2007,
p. 2. Available at [http://www.energy.gov/media/FY2007OperatingPlanForDOE.pdf].
117 U.S. Department of Energy. Office of Chief Financial Officer. FY2009 Congressional
Budget Request.
Volume 1, National Nuclear Security Administration. DOE/CF-024,
February 2008, p. 71, at [http://www.cfo.doe.gov/budget/09budget/Content/Volumes/
Volume1a.pdf].
118 “Nanos Tours Nevada Test Site,” Daily Newsbulletin, Los Alamos National Laboratory,
November 10, 2003, at [http://www.lanl.gov/orgs/pa/newsbulletin/2003/11/10/text04.shtml].

CRS-29
weapon.) In 1998, Secretary of Energy Bill Richardson called SCEs “a key part of
our scientific program to provide new tools and data that assess age-related
complications and maintain the reliability and safety of the nation’s nuclear
deterrent.”119 As they produce no chain reaction, the Clinton Administration saw
them as consistent with the CTBT. Critics counter that they would help design new
weapons without testing; are unnecessary; may look like nuclear tests if not
monitored intrusively; and are inconsistent with the spirit of a CTBT, which, critics
believe, is aimed at halting nuclear weapons development, not just testing. NNSA
stated that subcritical experiments cost between $5 million and $30 million.120 (For
further information on subcritical experiments and test readiness, see CRS Report
RL32130, Nuclear Weapon Initiatives: Low-Yield R&D, Advanced Concepts, Earth
Penetrators, Test Readiness
, by Jonathan Medalia.)
The 23 SCEs held so far are: 1997: Rebound, July 2; Holog, September 18;
1998: Stagecoach, March 25; Bagpipe, September 26; Cimarron, December 11;
1999: Clarinet, February 9; Oboe, September 30; Oboe 2, November 9; 2000: Oboe
3, February 3; Thoroughbred, March 22; Oboe 4, April 6; Oboe 5, August 18; Oboe
6, December 14; 2001: Oboe 8, September 26; Oboe 7 (held after Oboe 8), December
13; 2002: Vito (jointly with U.K.), February 14; Oboe 9, June 7; Mario, August 29;
Rocco, September 26; 2003: Piano, September 19; 2004: Armando, May 25; 2006:
Krakatau (jointly with U.K.), February 23; Unicorn, August 30. NNSA’s FY2006
request stated that, for pit certification, “The major activities in FY2006 include the
preparation and execution of subcritical experiments to confirm nuclear performance
of the W88 warhead with a newly-manufactured pit.”121 NNSA’s FY2007 request
states, “The Pit Campaign Support Activities at NTS provide support in fielding
subcritical experiments essential to pit certification with completion of activities at
the end of FY2006. There is no funding provided for these activities in FY2007. All
subcritical experiment activities in support of the LANL-manufactured W88 pit
certification effort will be completed in FY2006.”122 NNSA stated to CRS in March
2006 that Unicorn is the last SCE supporting the W88 pit program, but SCEs for
other purposes are anticipated. In March 2007, NNSA stated to CRS that
“Subcritical experiments are not currently being scheduled by the laboratories until
the FY2008 time frame.”
The laboratories have conducted two other types of experiments involving
plutonium at NTS. “Thermos” experiments are material property studies. NNSA
119 U.S. Department of Energy. “DOE to Conduct Fourth Subcritical Experiment; Scientific
Data to Help Ensure the Safety and Reliability Of the Stockpile Without Nuclear Testing,”
press release, September 23, 1998.
120 U.S. Department of Energy. Office of Management, Budget and Evaluation/CFO. FY
2006 Congressional Budget Request.
Volume 1, National Nuclear Security Administration.
DOE/ME-0046, February 2005, p. 88, at [http://www.mbe.doe.gov/budget/06budget/
Content/Programs/Vol_1_NNSA_2.pdf].
121 Ibid., p. 177.
122 U.S. Department of Energy. Office of Chief Financial Officer. FY 2007 Congressional
Budget Request.
Volume 1, National Nuclear Security Administration. DOE/CF-002,
February 2006, p. 192, at [http://www.mbe.doe.gov/budget/07budget/Content/Volumes/
Vol_1_NNSA.pdf].

CRS-30
stated in March 2007 that they do not use enough plutonium to sustain a chain
reaction, and the plutonium “does not approximate any part of weapons design.”
Twelve such experiments were conducted between February and May 2007; as of
September 2007, no more were planned.123 The Joint Actinide Shock Physics
Experimental Research (JASPER) Facility is a gas gun that shoots a high-velocity
projectile at a plutonium target to produce “high shock pressures, temperatures, and
strain rates similar to that of a nuclear weapon” in the plutonium. According to
NNSA, the resulting data help “refine the computer codes used to certify the U.S.
nuclear stockpile.124 Seventy shots were conducted between March 2001 and July
2007, of which 27 used plutonium and 43 used surrogate materials.
Test Readiness: President Clinton directed DOE to be prepared to conduct a
nuclear test within three years of a decision to do so. Yet a September 2002 report
by DOE’s Office of Inspector General found this ability “at risk.”125 In January 2002
the Nuclear Posture Review briefing called for an unspecified acceleration of nuclear
test readiness, and in March 2002 the Panel to Assess the Reliability, Safety, and
Security of the United States Nuclear Stockpile assessed that “test readiness should
be no more than three months to a year.”126 The FY2003 National Defense
Authorization Act, P.L. 107-314, sec. 3142, required the Secretary of Energy to
report on alternative test readiness postures and recommend the optimal readiness
posture. The resulting report argued that the three-year posture was increasingly at
risk and recommended moving to an 18-month readiness posture by the end of
FY2005.127
The FY2004 Weapons Activities request included $24.9 million to reduce the
posture from 3 years to 18 months. The National Defense Authorization Act and the
Energy and Water Development Appropriations Act provided the funds requested.
Conferees on the latter expected NNSA to focus on a program that can meet the
current 24-month requirement “before requesting significant additional funds to
pursue a more aggressive goal of an 18-month readiness posture.”128 In contrast, the
FY2004 National Defense Authorization Act (P.L. 108-136, sec. 3112) stated,
123 Information provided by National Nuclear Security Administration, September 19, 2007.
124 U.S. Department of Energy. National Nuclear Security Administration. Nevada Site
Office. “Joint Actinide Shock Physics Experimental Research (JASPER),” DOE/NV-1015,
September 2004, at [http://www.nv.doe.gov/library/factsheets/DOENV_1015.pdf].
125 U.S. Department of Energy. Office of Inspector General. Office of Audit Services.
National Nuclear Security Administration’s Test Readiness Program, Audit Report,
September 2002, p. 1.
126 Letter report from John Foster, Chairman, Panel to Assess the Reliability, Safety, and
Security of the United States Nuclear Stockpile, to Senator Carl Levin, Chairman,
Committee on Armed Services, U.S. Senate, March 15, 2002, p. ES-2, at [http://
www.fas.org/nuke/control/ctbt/text/foster01.doc].
127 U.S. Department of Energy. National Nuclear Security Administration. Nuclear Test
Readiness.
Report to Congress, April 2003, p. 5-8.
128 U.S. Congress. Committee of Conference. Making Appropriations for Energy and Water
Development for the Fiscal Year Ending September 30, 2004, and for Other Purposes,
H.Rept. 108-357, to accompany H.R. 2754, 108th Congress, 1st Session, 2003, p. 159-160.

CRS-31
“Commencing not later than October 1, 2006, the Secretary of Energy shall achieve,
and thereafter maintain, a readiness posture of not more than 18 months for
resumption by the United States of underground tests of nuclear weapons.”
In testimony before the Senate Armed Services Committee on March 24, 2004,
NNSA Administrator Linton Brooks said that NNSA’s goal “is to achieve the
18-month test readiness posture called for in the Defense Authorization Act.”129 The
FY2005 National Defense Authorization Act provided the full $30.0 million
requested for test readiness. In the FY2005 energy and water bill, the House
Appropriations Committee recommended reducing the Primary Assessment
Technologies campaign request of $81.5 million, which included $30.0 million for
test readiness, by $15.0 million “to limit the enhanced test readiness initiative to the
goal of achieving a 24-month test readiness posture. The Committee continues to
oppose the 18-month test readiness posture.”130 The FY2005 Consolidated
Appropriations Act reduced this campaign by $7.5 million.
NNSA’s FY2006 test readiness request was $25.0 million “to continue
improving the state of readiness to reach an 18-month test-readiness posture in
FY2006.”131 In a Senate Armed Services Committee hearing on February 15, 2005,
Senator John Warner asked Secretary of Energy Samuel Bodman whether DOE
would meet the 18-month test readiness requirement by October 1, 2006. Secretary
Bodman replied, “We continue to be committed to that requirement of the law” and
was informed that DOE is on track to meet the October 1 deadline.132 In testimony
before the Senate Appropriations Committee’s Energy and Water Development
Subcommittee on April 14, 2005, Ambassador Brooks explained the rationale for the
18-month posture: “Shorter than that, and you were paying money for readiness you
couldn’t use, because the experiment [the nuclear test] wouldn’t be ready. Longer
than that, and you were running the risk of being ready to test to find out whether you
had corrected an important problem, but the test site wasn’t ready.”133 The House
Appropriations Committee continued to favor a 24-month posture and stated that the
Reliable Replacement Warhead program “obviates any reason to move to a
129 U.S. Congress. Senate. Committee on Armed Services. Subcommittee on Strategic
Forces. Hearing on strategic forces, March 24, 2004, transcript by FDCH e-Media, Inc.
Testimony of Ambassador Linton Brooks, Administrator, National Nuclear Security
Administration.
130 U.S. Congress. House. Committee on Appropriations. Energy and Water Development
Appropriations Bill, 2005,
H.Rept. 108-554, to accompany H.R. 4614, 108th Congress, 2nd
Session, 2004, p. 116.
131 Department of Energy, FY 2006 Congressional Budget Request, Volume 1, p. 93.
132 U.S. Congress. Senate. Committee on Armed Services. Hearing on FY2006 budget
request for Atomic Energy Defense Activities of DOE and NNSA, February 15, 2005,
transcript by FDCH e-Media, Inc. Testimony of Samuel Bodman, Secretary of Energy.
133 U.S. Congress. Senate. Committee on Appropriations. Subcommittee on Energy and
Water Development. Hearing on FY2006 appropriations for NNSA, April 14, 2005,
transcript by FDCH e-Media, Inc. Testimony of Ambassador Linton Brooks, Under-
secretary, Nuclear Security, [and] Administrator, National Nuclear Security Administration.

CRS-32
provocative 18-month test readiness posture.”134 The Energy and Water
Development Appropriations Act reduced test readiness funding to $20.0 million;
conferees directed DOE to maintain the 24-month posture. The National Defense
Authorization Act also provided $20.0 million; the accompanying conference report
did not address the readiness posture. (See Legislation, below.)
For FY2007, NNSA requested $14.8 million for test readiness and noted that
the target test readiness posture for FY2006-FY2011, 24 months, was achieved in
FY2005.135 The House Armed Services Committee’s report on FY2007 defense
authorization stated, “While the committee has no indication of the need to resume
underground nuclear testing in the near future, it does believe that maintaining the
18 month readiness posture as directed by Congress is important to national security.
The committee notes that funding shortfalls have precluded the Department of
Energy from achieving the 18 month readiness posture as required by law.”136 In the
FY2007 Energy and Water Development Appropriations Bill (H.R. 5427), the House
provided the requested amount, and the Senate Appropriations Committee (in S.Rept.
109-274) recommended providing that amount. NNSA requests no funds under test
readiness for FY2008, noting that the program has achieved its goal of a 24-month
readiness posture, current capabilities will be maintained through other parts of the
budget, and “a more forward looking program is planned.”137 The House Armed
Services Committee made no mention of test readiness in its report, while the Senate
Armed Services Committee provided no funds, as requested. The House
Appropriations Committee sharply criticized the decision not to request funds, and
added funds:
The Committee supports the 24-month test readiness posture at the Nevada Test
Site and provides an additional $20,000,000 to restore the funding in the
Administration’s budget request which terminated the activity. The Committee
is baffled by the Administration’s decision to eliminate funding for nuclear test
readiness after four budget cycles of insisting that shortening to an 18-month test
readiness posture was required for national security reasons.... In the fiscal year
2008 budget request, the NNSA proposes what the Committee believes to be a
wasteful investment by allowing the restored test readiness activities to be
degraded.138
134 U.S. Congress. House. Committee on Appropriations. Energy and Water Development
Appropriations Bill, 2006.
H.Rept. 109-86, to accompany H.R. 2419, 109th Congress, 1st
Session, 2005, p. 134.
135 Department of Energy, FY 2007 Congressional Budget Request. Volume 1, National
Nuclear Security Administration, p. 97.
136 U.S. Congress. House. Committee on Armed Services. National Defense Authorization
Act for Fiscal Year 2007,
H.Rept. 109-452 to accompany H.R. 5122, 109th Congress, 2nd
Session, 2006, p. 464.
137 U.S. Department of Energy. Office of Chief Financial Officer. FY 2008 Congressional
Budget Request.
Volume 1, National Nuclear Security Administration. DOE/CF-014,
February 2007, p. 101. Available at [http://www.mbe.doe.gov/budget/08budget/Content/
Volumes/Vol_1_NNSA.pdf].
138 U.S. Congress. House. Committee on Appropriations. Energy and Water Development
(continued...)

CRS-33
Section 3112 of the conference version of H.R. 1585, the FY2008 defense
authorization bill, repealed a provision (P.L. 108-136, section 3113; 50 U.S.C.
2528a) requiring an 18-month nuclear test posture, and required the Secretary of
Energy to submit a report on nuclear test readiness every two years. For test
readiness, the FY2008 estimate is $4.9 million and the FY2009 request is $10.4
million.139 NNSA stated that it had achieved a 24-month test readiness posture in
FY2007, but that “forecasted budget levels resulted in a change in the test readiness
posture target to 24 to 36 months.”140 The FY2009 defense authorization bills as
passed by the House and as reported by the Senate Armed Services Committee
include the requested amount for test readiness.
In a statement by Ambassador Andrej Logar on behalf of the European Union
(EU), “The EU urges all States to dismantle all their nuclear testing sites in a manner
that is transparent and open to the international community.”141
Table 1. U.S. Nuclear Tests by Calendar Year
1945-1949
6
1960-1964
202
1980-1984
92
1950-1954
43
1965-1969
231
1985-1989
75
1955-1959
145
1970-1974
137
1990-1992
23
1975-1979
100
Total
1054
Source: U.S. Department of Energy.
Note: These figures include all U.S. nuclear tests, of which 24 were joint U.S.-U.K. tests conducted
at the Nevada Test Site between 1962 and 1991. They reflect data on unannounced tests that DOE
declassified on December 7, 1993. They exclude the two atomic bombs that the United States dropped
on Japan in 1945. On June 27, 1994, Secretary O’Leary announced that DOE had redefined three
nuclear detonations (one each in 1968, 1970, and 1972) as separate nuclear tests. This table reflects
these figures. She also declassified the fact that 63 tests, conducted from 1963 through 1992, involved
more than one nuclear explosive device.
CTBT Pros and Cons
The CTBT is contentious. For a detailed analysis of the case for and against the
treaty, see CRS Report RL34394, Comprehensive Nuclear-Test-Ban Treaty: Issues
and Arguments.
Key arguments include the following:
138 (...continued)
Appropriations Bill, 2008, H.Rept. 110-185, to accompany H.R. 2641, 110th Congress, 1st
Session, 2007, p. 102.
139 Department of Energy, FY2009 Congressional Budget Request, vol. 1, p. 133.
140 Ibid., p. 135.
141 Statement by H.E. Ambassador Andrej Logar, Permanent Representative of Slovenia, on
Behalf of the European Union, presented to the Preparatory Committee for the 2010 Review
Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons,
Second Session, Geneva, April 28-May 9, 2008, p. 6, at [http://www.reachingcriticalwill.
org/legal/npt/prepcom08/statements/EUApril28.pdf].

CRS-34
Can the United States maintain deterrence without testing? The treaty’s
supporters hold that U.S. programs can maintain existing, tested weapons without
further testing, pointing to 12 annual assessments that these weapons remain safe and
reliable, and claim that these weapons meet any deterrent needs. Opponents maintain
that there can be no confidence in existing warheads, as many minor modifications
will change them from tested versions, so testing is needed to restore and maintain
confidence. They see deterrence as dynamic, requiring new weapons to counter new
threats, and assert that these weapons must be tested.
Are monitoring and verification capability sufficient? “Monitoring” refers to
technical capability; “verification” to its adequacy to maintain security. Supporters
hold that advances in monitoring make it hard for an evader to conduct undetected
tests. They claim that any such tests would be too small to affect the strategic
balance. Opponents see many opportunities for evasion and believe that clandestine
tests could put the United States at a serious disadvantage.
How might the treaty affect nuclear nonproliferation and disarmament?
Supporters claim that the treaty makes technical contributions to nonproliferation,
such as limiting weapons programs; some supporters believe that nonproliferation
requires progress toward nuclear disarmament, with the treaty a key step. Opponents
believe that a strong nuclear deterrent is essential for nonproliferation, that
nonproliferation and disarmament are unrelated, and that this nation has taken many
nonproliferation and disarmament actions that the international community ignores.
Legislation
H.R. 2642 (Edwards). Supplemental Appropriations Act, 2008. Senate
Amendment 4803 included an additional $5.0 million “for a United States
contribution to the Comprehensive Test Ban Treaty International Monitoring
System.” The amendment passed the Senate, 75-22, on May 22.
H.R. 5658 (Skelton). Duncan Hunter National Defense Authorization Act for
Fiscal Year 2009. Reported by House Committee on Armed Services (H.Rept. 110-
146) May 16. The Administration requested $10.4 million for nuclear test readiness,
and the bill contained that amount. Measure passed House, 384-23, on May 22 (roll
no. 365).
S. 3001 (Levin). National Defense Authorization Act for Fiscal Year 2009.
Reported by Senate Committee on Armed Services (S.Rept. 110-335) May 12. The
Administration requested $10.4 million for nuclear test readiness, and the bill
contained that amount.
H.Res. 68 (Woolsey). Recognizing the dangers posed by nuclear weapons.
Urges the President, among other things, to “reaffirm the moratorium on nuclear
testing and work for ratification of the Comprehensive Test Ban Treaty at the earliest
possible date.” Introduced January 16, 2007, and referred to the House Committees
on Armed Services and Foreign Affairs. Referred to the Subcommittee on Terrorism,
Nonproliferation, and Trade on February 5, 2007.

CRS-35
H.Res. 227 (Woolsey). “Calling for the adoption of a Sensible, Multilateral
American Response Terrorism (SMART) security platform for the 21st century.”
Calls for a U.S. security policy that, among other things, would reduce the spread of
weapons of mass destruction by adhering to the CTBT. Referred to House Committee
on Foreign Affairs, March 7, 2007.
H.Res. 882 (Tauscher). “Expressing the sense of the House of Representatives
that the Senate should initiate a bipartisan process to give its advice and consent to
ratification of the Comprehensive Nuclear-Test-Ban Treaty.” Introduced December
17, 2007, and referred to the House Committee on Foreign Affairs.
Chronology
06/00/09 —
An international scientific conference is to be held in Vienna to
present the results of the International Scientific Studies project of the
Preparatory Commission for the Comprehensive Nuclear-Test-Ban
Treaty Organization.
05/27/08 —
Senator John McCain said he would “tak[e] another look at the
Comprehensive Test Ban Treaty to see what can be done to overcome
the shortcomings that prevented it from entering into force.”
02/25/08 —
The United States paid $23.8 to the Comprehensive Nuclear-Test-Ban
Treaty Preparatory Commission, restoring its voting rights in the
commission.
01/29/08 —
Colombia, one of the Annex 2 states that must ratify the CTBT for it
to enter into force, became the 144th nation to ratify the treaty.
12/17/07 —
Representative Tauscher introduced H.Res. 882, expressing the sense
of the House that the Senate should initiate a bipartisan process to
give its advice and consent to ratification of the CTBT.
11/26/07 —
The conference report on H.R. 1585, the
FY2008 defense
authorization bill, was ordered to be printed. The bill provided for
biennial reports on U.S. nuclear test readiness and dropped a
provision in the Senate bill expressing the sense of Congress that “the
Senate should ratify” the CTBT.
12/05/07 —
By a vote of 176 for, 1 against (United States), and 4 abstentions, the
U.N. General Assembly adopted resolution A/RES/62/59 stressing
the importance of achieving the earliest entry into force of the CTBT.
11/26/07 —
Bahamas became the 141st nation to ratify the CTBT.
11/19/07 —
Former Secretary of Defense Harold Brown and former Director of
Central Intelligence John Deutch suggested a five-year renewable
CTBT in lieu of the current treaty.

CRS-36
11/14/07 —
The Preparatory Commission for the Comprehensive Nuclear-Test-
Ban Treaty Organization concluded its 29th meeting.
10/24/07 —
Senator Jon Kyl delivered a speech critical of the CTBT and of
Section 3122 of H.R. 1585, the FY2008 National Defense
Authorization Act, expressing the sense of Congress that the Senate
should ratify the CTBT. Senator Kyl included a letter signed by 41
Senators opposing the treaty and Section 3122.
09/00/07 —
The United Nations held the fifth conference on facilitating CTBT
entry into force on September 17 and 18 in Vienna, Austria.
06/22/07 —
The Preparatory Commission for the Comprehensive Nuclear-Test-
Ban Treaty Organization concluded its 28th meeting.
06/04/07 —
The Senate Armed Services Committee reported S. 1547, FY2008
National Defense Authorization Act. Section 3122, Sense of
Congress on the Nuclear Nonproliferation Policy of the United States
and the Reliable Replacement Warhead Program, included a
provision, “the Senate should ratify the Comprehensive Nuclear-Test-
Ban Treaty.”
06/04/07 —
The United States paid $10.0 million toward the International
Monitoring System to the Comprehensive Test Ban Treaty
Organization Preparatory Commission.
03/29/07 —
The Comprehensive Nuclear-Test-Ban
Treaty
Organization
Preparatory Commission certified the 200th and 201st International
Monitoring System stations.
01/31/07 —
Mikhail Gorbachev called on nuclear weapon states to ratify the
CTBT.
01/04/07 —
Four former government officials urged “[i]nitiating a bipartisan
process with the Senate ... to achieve ratification of the
Comprehensive Test Ban Treaty.”
11/17/06 —
The Preparatory Commission for the Comprehensive Nuclear-Test-
Ban Treaty Organization concluded its 27th meeting.
10/16/06 —
The United States confirmed that the North Korean event of October
9 was a nuclear test.
10/09/06 —
North Korea claimed to have conducted its first nuclear test; most
reports placed the explosive yield of the test at one kiloton or less.
10/03/06 —
North Korea declared that it will conduct a nuclear test.
9/28/06 —
Representative Tauscher introduced H.Res. 1059, calling on the
Senate to give its advice and consent to CTBT ratification.

CRS-37
9/20/06 —
Fifty-nine foreign ministers called on states that have not done so to
ratify the treaty.
8/30/06 —
The United States conducted its 23rd subcritical experiment,
“Unicorn,” at the Nevada Test Site.
6/00/06 — The
26th meeting of the Preparatory
Commission
for
the
Comprehensive Nuclear Test Ban Treaty Organization was held June
20-23.
2/23/06 —
The United States and United Kingdom conducted a subcritical
experiment, “Krakatau,” at the Nevada Test Site.
For earlier chronology, see the Appendix.
For Additional Reading
Andreasen, Steve, and Sidney Drell, “Untested Solutions,” Foreign Affairs, March/
April 2005: 173-174. [Responds to Deutch, “A Nuclear Posture for Today.”]
Arms Control Association, “Congress Must Remedy Past U.S. Funding Shortfalls for
Global Nuclear Test Monitoring System,” media advisory, May 21, 2007.
Bailey, Kathleen, and Robert Barker. “Why the United States Should Unsign the
Comprehensive Test Ban Treaty and Resume Nuclear Testing.” Comparative
Strategy.
April-June 2003: 131-138.
Brown, Harold. “New Nuclear Realities.” Washington Quarterly. Winter 2007-08,
pp. 7-22.
Brown, Harold, and John Deutch. “The Nuclear Disarmament Fantasy.” Wall Street
Journal, November 19, 2007, p. 19.
Comprehensive Nuclear-Test-Ban Treaty Organization. Data on payments as of May
15, 2008. [http://www.ctbto.org/prepcom/0507_collections.pdf] (Data at this
link are updated from time to time.)
Conference on Facilitating the Entry into Force of the Comprehensive Nuclear-Test-
Ban Treaty, “Draft final declaration and measures to promote the entry into
force of the Comprehensive Nuclear-Test-Ban Treaty,” September 17-18, 2007,
6 p. [http://www.ctbto.org/reference/article_xiv/2007/CTBT-ART-XIV-2007-
WP1.pdf].
Deutch, John, “A Nuclear Posture for Today,” Foreign Affairs, January/February
2005: 49-60.

CRS-38
Federation of American Scientists. Nuclear Weapons/Nuclear Testing site.
[http://www.fas.org/main/content.jsp?formAction=315&projectId=7&project
Name=Nuclear+Weapons&contentTypeId=42&contentTypeDesc=Nuclear+
Testing].
Fox, Jon. “Senators Call for Test Ban Treaty Ratification.” Global Security
Newswire, June 8, 2007. [http://www.nti.org/d_newswire/issues/2007/6/8/
3bfd80f4-0fe7-4c75-82e5-8bfe1d1dc9cd.html].
Gallucci, Robert, “Nuclear Shockwaves: Ramifications of the North Korean Nuclear
Test,” Arms Control Today, November 2006.
Giacomo, Carol, “Testing Is New Wrinkle in US-India Nuclear Deal,” Reuters
newswire, April 24, 2006.
Gorbachev, Mikhail, “The Nuclear Threat,” Wall Street Journal, January 31, 2007:
13.
Grossman, Elaine, “Senate Debates Authorization Measure on Ratifying Test Ban
Treaty,” Inside the Pentagon, July 12, 2007.
Hafemeister, David, “Progress in CTBT Monitoring Since Its 1999 Senate Defeat,”
Science and Global Security, no. 15, 2007, pp. 151-183.
Hansen, Keith, “CTBT: Forecasting the Future,” Bulletin of the Atomic Scientists,
March/April 2005: 50-57.
“Joint Ministerial Statement on the CTBT,” New York, September 20, 2006.
Kessler, Glenn, “Signs Stir Concern North Korea Might Test Nuclear Bomb,”
Washington Post, April 23, 2005: 13.
Kralev, Nicholas, “Unpaid U.S. Dues Hit Nuke-Test Monitoring,” Washington
Times, May 24, 2007, p. 13.
Kyl, Senator Jon, “Defense Authorization” [speech critical of the CTBT],
Congressional Record, October 24, 2007, pp. S13357-S13358.
Lay, Jennie, “Test Site Rising,” Bulletin of the Atomic Scientists, May/June 2007, pp.
58-62.
Linzer, Dafna, and Thomas Ricks, “U.S. Waits for Firm Information on Nature and
Success of [North Korean Nuclear] Device,” Washington Post, October 11,
2006: 14.
Lynch, Colum, “Test Ban Network Probably Detected Quake but Was Unequipped
to Warn of Tsunami,” Washington Post, December 30, 2004: 24.
Mackby, Jenifer, and Ola Dahlman, “Nuclear Fears, Alarming Arrears,” Baltimore
Sun, July 25, 2007.

CRS-39
Monroe, Robert, VADM USN (Ret.), “North Korea’s Impact on Nuclear Testing,”
Comparative Strategy, vol. 26, 2007, pp. 55-58.
Monroe, Robert, VADM, USN (Ret.), “Nuclear Testing Realities,” Washington
Times, December 4, 2007, p. 16.
National Academy of Sciences. Committee on Technical Issues Related to
Ratification of the Comprehensive Nuclear Test Ban Treaty. Technical Issues
Related to the Comprehensive Nuclear Test Ban Treaty.
Washington, National
Academy Press, 2002. [http://www.nap.edu/catalog.php?record_id=10471].
“Nuclear Disarmament: The Long, Long Half-Life,” The Economist, June 10, 2006.
Parakilas, Jacob, “Congress Cuts CTBTO Funding,” Arms Control Today, December
2005: 25.
Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty
Organization, “Want to Join a Global Scientific Project? International
Scientific Studies to Evaluate the CTBT Verification Regime,” c. April 2008,
at [http://www.ctbto.org/reference/outreach/100408_issleaflet_web.pdf].
Ramaker, Jaap, Jenifer Mackby, Peter Marshall, and Robert Geil, The Final Test: A
History of the Comprehensive Nuclear-Test-Ban Treaty Negotiations, Vienna,
Austria, Provisional Technical Secretariat of the Preparatory Commission for
the Comprehensive Nuclear-Test-Ban Treaty Organization, 2003, 291 p.
Richards, Paul, “Forensic Seismology and CTBT Verification,” CTBTO Spectrum,
January 2007, pp. 1, 6, 19.
Robbins, Carla Anne, “U.S. Weighs Whether to Build Some New Nuclear
Warheads,” Wall Street Journal, December 14, 2005: 1, 15.
Russian Federation. Ministry for Atomic Energy and Ministry of Defense. USSR
Nuclear Weapons Tests and Peaceful Nuclear Explosions, 1949 through 1990.
1996. 63 p.
Russian Federation. Ministry for Atomic Energy. Catalog of Worldwide Nuclear
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York Times (online version), October 3, 2006.
Sanger, David, “U.S. in Warning to North Korea on Nuclear Test,” New York Times,
May 16, 2005: 1.
Sanger, David, “North Koreans Say They Tested Nuclear Device,” New York Times,
October 9, 2006: 1.
Scowcroft, Brent, and Daniel Poneman, “Confront North Korea,” Wall Street
Journal, May 26, 2005: 12.

CRS-40
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Appendix. Chronology, 1992-2005
09/23/92 — The United States conducted its most recent nuclear test, “Divider.”
10/02/92 — President Bush signed the FY1993 Energy and Water Development
Appropriations Act, P.L. 102-377; sec. 507 restricted U.S. nuclear
testing.
10/13/92 — Russia announced an extension of its test moratorium at least to mid-
1993.
01/13/93 — President François Mitterrand said France would extend its test
moratorium as long as the United States and Russia did.
04/24/93 — At the Vancouver summit, Presidents Clinton and Yeltsin agreed that
negotiations on a multilateral test ban should begin soon.
07/03/93 — President Clinton announced his plan to continue the test moratorium
through September 1994 as long as no other nation tests.
08/10/93 — The Conference on Disarmament (CD) gave its Ad Hoc Committee
on a Nuclear Test Ban a mandate to negotiate a CTBT.
10/05/93 — China held the world’s first nuclear test since September 1992.
01/25/94 — The Conference on Disarmament opened its 1994 session in Geneva,
with negotiation of a CTBT its top priority.
03/15/94 — The United States extended its test moratorium through September
1995.
06/10/94 — China conducted an underground nuclear test.
09/26/94 — President Yeltsin, in an address to the U.N. General Assembly, said,
“Russia favors signing this treaty [the CTBT] next year.”
10/07/94 — China conducted an underground nuclear test.
01/24/95 — President Clinton said in his State of the Union address, “The United
States will lead the charge to extend indefinitely the Nuclear Non-
Proliferation Treaty [and] to enact a comprehensive nuclear test ban.”
01/30/95 — President Clinton continued the U.S. moratorium until a CTBT enters
into force, assuming it is signed before September 30, 1996.
05/11/95 — The Nuclear Non-Proliferation Treaty Review and Extension Confe-
rence agreed to extend that treaty indefinitely, and by reference called
for completing CTBT negotiations not later than 1996.
05/15/95 — China conducted a nuclear test, its fourth since September 1992.
06/13/95 — President Jacques Chirac announced that France would conduct eight
nuclear tests in the South Pacific between September 1995 and May
1996.
08/04/95 — The Senate tabled, 56 to 44, an amendment by Senator Exon and
others to delete $50 million for conducting hydronuclear tests (those
producing extremely low nuclear yield). The amendment was to S.
1026, the FY1996 National Defense Authorization Bill.
08/10/95 — France announced that once it completed its nuclear test program, it
would support a CTBT that bans all nuclear tests of any yield.
08/11/95 — President Clinton announced his decision to pursue a “true zero
yield” CTBT, banning all nuclear tests regardless of yield, accom-
panied by six “safeguards” to assure confidence in U.S. nuclear
weapons under a CTBT.
08/17/95 — China conducted a nuclear test, its fifth since September 1992.
09/05/95 — France conducted a nuclear test, its first since 1991.

CRS-43
12/13/95 — A U.N. General Assembly resolution, passed 85-18, “strongly de-
plores” current nuclear testing and “strongly urges” an immediate end
to testing.
01/23/96 — In his State of the Union Address, President Clinton stated,”We must
end the race to create new nuclear weapons by signing a truly
comprehensive nuclear test ban treaty — this year.”
01/27/96 — France held the sixth nuclear test in its test series.
01/29/96 — President Chirac announced “the final end to French nuclear tests.”
03/07/96 — The Washington Times reported U.S. intelligence agencies have
ambiguous evidence that Russia may have conducted a nuclear test
in January 1996.
04/19/96 — President Yeltsin formally endorsed a zero-yield CTBT and reserved
the right to resume testing if Russia’s supreme interests are
threatened. The next day, the Group of Seven plus Russia expressed
their commitment to complete and sign a zero-yield CTBT by
September 1996.
05/28/96 — Ambassador Jaap Ramaker of the Netherlands, Chairman of the CD’s
Ad Hoc Committee on a Nuclear Test Ban, tabled a draft text of a
CTBT incorporating compromises on key outstanding issues.
06/04/96 — France and the United States signed an agreement to share
information relevant to maintaining nuclear weapons.
06/08/96 — China held a nuclear test and declared that after one more test it
would join an international moratorium on nuclear explosions.
06/20/96 — India stated it would not sign a CTBT unless the five declared nuclear
weapon states agreed to a timetable to give up their nuclear weapons.
06/26/96 — The Senate tabled, 53-45, an amendment by Senators Kyl and Reid
to the FY1997 National Defense Authorization Bill to permit U.S.
nuclear testing after September 30, 1996, under certain conditions if
the Senate had not given its advice and consent to ratification of a
CTBT.
07/23/96 — The United States and Russia announced their joint support for the
existing draft CTBT. While this draft did not fully satisfy either
nation, they saw it as acceptable and the only route to achieving a
CTBT in 1996.
07/29/96 — China conducted what it said would be its last nuclear test, and
pledged to begin a moratorium on testing on July 30.
08/07/96 — China and the United States reportedly reached an agreement on
modifying the draft treaty so as to resolve China’s concerns over
CTBT verification, clearing the way for China to support the treaty.
08/20/96 — India vetoed the draft CTBT in the CD, barring the treaty from going
to the U.N. General Assembly as a CD document.
08/23/96 — Australia asked the U.N. General Assembly to begin consideration of
the draft CTBT on September 9.
09/10/96 — The U.N. General Assembly adopted, 158 to 3 (with 5 abstentions
and 19 nations not voting), the draft CTBT negotiated at the CD.
09/24/96 — The CTBT was opened for signing; President Clinton and others
signed.
11/20/96 — The Preparatory Commission for the Comprehensive Test Ban Treaty
Organization (CTBTO) began its first meeting.

CRS-44
07/02/97 — The Department of Energy conducted its first subcritical experiment,
“Rebound,” at the Nevada Test Site. It conducted one more in 1997.
08/28/97 — The Washington Times reported Administration officials as saying
Russia may have conducted a nuclear explosion on August 16.
09/22/97 — President Clinton submitted the CTBT to the Senate for its advice and
consent to ratification.
11/04/97 — The Washington Post reported the Administration formally dropped
its claim that a seismic event of August 16, 1997, was a Russian
nuclear test.
01/21/98
Senator Jesse Helms, in a letter to President Clinton, said “the CTBT
is very low on the [Senate Foreign Relations] Committee’s list of
priorities.”
01/27/98
In his State of the Union address, President Clinton asked the Senate
to approve the CTBT this year and announced that four former
Chairmen of the Joint Chiefs of Staff had endorsed the treaty.
03/25/98
The Department of Energy conducted its third subcritical experiment,
“Stagecoach,” at the Nevada Test Site. It conducted two more in
1998.
04/06/98 —
Britain and France became the first declared nuclear weapon states to
ratify the CTBT, depositing instruments of ratification with the U.N.
05/11/98 —
Prime Minister Vajpayee announced India conducted three nuclear
tests.
05/13/98 —
India announced that it conducted two nuclear tests.
05/28/98 —
Pakistan announced that it conducted five nuclear tests.
05/30/98 —
Pakistan announced that it conducted one nuclear test.
06/05/98 —
The foreign ministers of China, France, Russia, the United Kingdom,
and the United States, in a joint communique, condemned the Indian
and Pakistani nuclear tests, urged India and Pakistan to refrain from
weaponizing or deploying nuclear weapons, and called on them to
adhere to the CTBT “immediately and unconditionally.”
09/23/98 —
Pakistan’s Prime Minister, Nawaz Sharif, in an address to the U.N.,
said his nation would adhere to the CTBT if other nations lifted
economic sanctions, as long as India refrained from testing.
12/00/98 —
Secretary of Energy Bill Richardson and Secretary of Defense
William Cohen submitted the third annual nuclear stockpile
certification memorandum to the President stating, “The nuclear
stockpile has no safety or reliability concerns that require
underground testing at this time.”
02/09/99
The Department of Energy conducted its sixth subcritical experiment,
“Clarinet,” at the Nevada Test Site. It conducted two more in 1999.
05/25/99 —
The Cox Committee, in its report, stated its belief that China may be
continuing to conduct underground nuclear tests.
07/20/99 —
In separate press conferences, President Clinton and nine Senators
urged the Senate to consider the CTBT. A survey found 82% of
Americans want the treaty approved. All 45 Democratic Senators
wrote to Senator Helms urging him to hold hearings on the treaty and
to report it to the Senate.
07/26/99 —
Responding to the July 20 letter, Senator Helms stated that “I do not
share your enthusiasm for this treaty” and that the Senate Foreign

CRS-45
Relations Committee would consider it after amendments to the
ABM Treaty and the Kyoto Protocol.
09/30/99
Senator Lott proposed a unanimous-consent request that would bring
the CTBT to the Senate floor for 10 hours of debate beginning
October 6, and then to a vote.
10/08/99
(1) States that had ratified the CTBT ended a three-day conference on
expediting entry into force. (2) The Senate began debate on the
treaty.
10/11/99
President Clinton wrote to Senators Lott and Daschle to request that
a vote on the CTBT be delayed.
10/13/99
The Senate rejected the CTBT, 48 for, 51 against, 1 present.
01/28/00
Secretary of State Albright announced that Gen. John Shalikashvili
(ret.) would head the Administration’s effort to achieve bipartisan
support for CTBT ratification, but the State Department indicated the
Administration did not expect to seek Senate approval of the treaty in
2000.
02/04/00
DOE conducted the ninth U.S. subcritical experiment, “Oboe 3.” It
held four more in 2000.
02/04/00 — Russia announced that it conducted seven subcritical experiments
between September 23, 1999, and January 8, 2000.
06/30/00
Russia ratified the CTBT.
11/03/00 — Russia announced that it completed its fifth and final series of
subcritical experiments for 2000 at Novaya Zemlya during the week
of October 30.
01/17/01
— Colin Powell, as nominee for Secretary of State,
said
the
Administration would not ask for CTBT ratification in this session of
Congress.
03/04/01
The New York Times reported U.S. intelligence experts were divided
on whether Russia had conducted clandestine tests over the past
several years.
06/26/01
The House Appropriations Committee declined to add funds to the
FY2002 Energy and Water Development Appropriations Bill to
increase nuclear test readiness, arguing the Secretary of Defense,
President, Armed Services Committees, and Congress must first
request or approve these funds.
09/26/01 — The National Nuclear Security Agency (NNSA) held the 14th U.S.
subcritical experiment, “Oboe 8.” It conducted one more in 2001.
11/11/01 — The Conference on Facilitating the Entry into Force of the CTBT
began on this date at U.N. headquarters in New York and ended
November 13.
02/15/02 — NNSA held the 16th U.S. subcritical experiment, and the first with
U.K. participation, “Vito.” It conducted three more subcritical
experiments, without U.K. participation, in 2002.
05/10/02 — The House passed H.R. 4546, the Bob Stump National Defense
Authorization Act for FY2003; it called for DOE to achieve the
ability to conduct a nuclear test within a year of a presidential
direction to test.
07/31/02
The National Academy of Sciences issued a report asserting that the
main technical concerns raised in regard to the CTBT are
manageable.

CRS-46
09/26/02
NNSA held the 19th U.S. subcritical experiment, “Rocco.”
02/00/03 — A House Policy Committee report recommended “a test readiness
program that could achieve an underground diagnostic [nuclear] test
within 18 months”; the Bipartisan Congressional Task Force on
Nonproliferation urged President Bush “not to resume nuclear
weapons testing.”
05/22/03 — The Senate passed, 98-1, S. 1050, the FY2004 National Defense
Authorization Bill. Sec. 3132 directed the Secretary of Energy to
achieve by October 1, 2006, and to maintain thereafter, the ability to
conduct a nuclear test within 18 months of a decision to test, unless
the Secretary determines that a different number of months is
preferable.
09/00/03
A conference on facilitating the CTBT’s entry into force was held in
Vienna, Austria, September 3-5.
09/19/03
NNSA held the 20th U.S. subcritical experiment, “Piano.”
10/30/03
The U.N. General Assembly’s First Committee (Disarmament and
International Security) approved a draft resolution, “A Path to Total
Elimination of Nuclear Weapons,” 146-2, with 16 abstentions. A
provision stressed the importance of achieving early entry into force
of the CTBT. The United States and India voted no; the U.S.
representative stated that he did so because of U.S. opposition to the
CTBT.
11/00/03
The 21st meeting of the CTBTO Preparatory Commission was held
November 10-13 in Vienna, Austria.
12/08/03 — The U.N. General Assembly adopted, 164-2, with 2 abstentions, a
resolution, “A Path to Total Elimination of Nuclear Weapons.”
01/06/04 —
Libya became the 109th nation to ratify the CTBT.
05/25/04 —
NNSA held the 21st U.S. subcritical experiment, “Armando.”
06/20/04 — In a joint statement, India and Pakistan agreed to reaffirm their
unilateral moratoria on nuclear testing, barring extraordinary events,
and to establish a dedicated and secure hotline between the two
foreign secretaries.
06/00/04
The 22nd meeting of the CTBTO Preparatory Commission was held
June 22-24 in Vienna, Austria.
09/24/04
Foreign ministers from 42 nations issue a statement calling entry into
force of the CTBT “more urgent today than ever before.”
12/03/04 — The U.N. General Assembly adopted, 177-2, with 4 abstentions, a
resolution, “Comprehensive Nuclear-Test-Ban Treaty.”
2/10/05
North Korea declared, “We ... have manufactured nukes for self-
defense to cope with the Bush Administration’s evermore
undisguised policy to isolate and stifle the DPRK.”
03/10/05 — The European Parliament passed a resolution that, among other
things, “reiterates its call for the USA ... to sign and ratify the
CTBT.”
05/00/05 — At the Nuclear Nonproliferation Treaty Review Conference, held
May 2-27, some nations criticized the United States for not ratifying
the CTBT.
05/16/05
The New York Times reported that on May 15, National Security
Advisor Stephen Hadley stated, “Action would have to be taken” if
North Korea conducted a nuclear test.

CRS-47
08/29/05
Egyptian Foreign Minister Ahmed Aboul Gheit reportedly stated that
Egypt would not ratify the CTBT until Israel joins the NPT.
09/00/05
A conference, Facilitating the Entry into Force of the Comprehensive
Nuclear Test Ban Treaty, was held September 21 to 23 at U.N.
Headquarters.
11/00/05 — The 25th session of the Preparatory
Commission
for
the
Comprehensive Nuclear-Test-Ban Treaty Organization was held
November 14 to 18.
12/08/05 — The U.N. General Assembly adopted, 168-2, a resolution on nuclear
disarmament that, among other things, urged nations to ratify the
CTBT.