Iran’s Nuclear Program and U.N. Sanctions Reimposition
Updated September 23, 2022
Iran’s Nuclear Program and U.N. Sanctions Reimposition
U.N. Security Council Resolution 2231 (2015), which the
The NPT, which Iran ratified in 1970, includes prohibitions
council adopted on July 20, 2015, implements the Joint
on obtaining or producing nuclear weapons Comprehensive
Comprehensive Plan of Action (JCPOA) and contains other
safeguards agreements are designed to enable the agency to
provisions concerning Iran’s nuclear program, Tehran’s
detect the diversion of nuclear material from declared
development of missiles, and arms transfers to and from
nuclear facilities, as well as to detect undeclared nuclear
Iran. In August 2020, the United States invoked the
activities and material.
resolution’s “snapback” mechanism, which requires the
Iran has also ceased implementing the Additional Protocol
Security Council to reimpose U.N. sanctions lifted pursuant
to its comprehensive safeguards agreement. Such protocols
to Resolution 2231 and the JCPOA.
increase the IAEA’s ability to investigate undeclared
The JCPOA, finalized in July 2015 by Iran and China,
nuclear facilities and activities in nonnuclear-weapon states
France, Germany, Russia, the United Kingdom, and the
by increasing the agency’s authority to inspect certain
United States (collectively known as the P5+1), requires
nuclear-related facilities and demand information from
Iran to implement constraints on its uranium enrichment
member states. Pursuant to its JCPOA commitments, Iran is
and heavy water nuclear reactor programs, as well as allow
required to implement provisionally its additional protocol;
the International Atomic Energy Agency (IAEA) to monitor
Tehran is to seek ratification of the protocol by the Iranian
Tehran’s compliance with the agreement. Prior to the
parliament no later than October 2023. Iran originally
JCPOA, these programs caused international concern
signed such an additional protocol in late 2003, but stopped
because they could both have produced fissile material for
implementing it in early 2006.
use in nuclear weapons.
Moreover, the IAEA no longer monitors JCPOA
Pursuant to the JCPOA, Tehran received relief from
restrictions which supplement Iran’s safeguards obligations
sanctions imposed by the European Union, United Nations,
and prohibit Iran from engaging in a number of dual-use
and United States. On the agreement’s January 16, 2016,
“activities which could contribute to the development of a
Implementation Day, the Security Council terminated
nuclear explosive device.” Should the JCPOA be
sanctions imposed by three previous resolutions on Iran; the
implemented as envisioned in the agreement, most of its
council adopted the first of these resolutions (1696) in 2006
nuclear-related restrictions will expire. In that case,
and the last (1929) in 2010. The sole operative Security
Tehran’s nuclear program will be governed indefinitely by
Council resolution concerning Iran’s nuclear program,
Iran’s obligations pursuant to the NPT, the government’s
Resolution 2231, also stipulates that the council, which has
IAEA comprehensive safeguards agreement and Additional
been seized of the “Iranian nuclear issue” since 2006, is to
Protocol, and the dual-use restrictions described above.
end its consideration of the matter in 2025. The resolution’s
U.N. Security Council Resolution 2231
snapback mechanism will then cease to be operational.
(2015) and Snapback
In May 2018, President Donald Trump issued a
In addition to its JCPOA-related provisions, Resolution
memorandum stating that the United States would no longer
2231 imposes other requirements on Iran. For example, the
participate in the JCPOA and would reimpose sanctions that
resolution restricts exports of missile-rated items to Iran
had been suspended pursuant to the agreement. Arguing
until October 2023; other restrictions concerning Iranian
that subsequent efforts by the remaining JCPOA
imports and exports of conventional weapons expired on
participants, known as the “P4+1,” were inadequate to
October 18, 2020. Despite lacking a direct connection to the
sustain the agreement’s benefits for Iran, the government
country’s nuclear program, previous arms restrictions, the
has undertaken some nuclear activities that exceed JCPOA-
first of which were imposed by Security Council Resolution
mandated limits.
1747 (2007), were part of a broad U.S.-led approach of
Iran’s Nuclear Program and Selected
pressuring Iran to comply with relevant council resolutions.
JCPOA Provisions
(For more on the arms restrictions, see CRS In Focus
Beginning in July 2019, the IAEA verified that some of
IF11429, U.N. Ban on Iran Arms Transfers and Sanctions
Iran’s nuclear activities were exceeding JCPOA-mandated
Snapback, by Kenneth Katzman.)
limits; the government has since increased the number of
According to Resolution 2231, a JCPOA participant can,
such activities. Tehran has also curtailed IAEA monitoring
after notifying the Security Council of an issue that the
of Iran’s JCPOA commitments, which supplement Tehran’s
government “believes constitutes significant non-
obligations pursuant to its IAEA comprehensive safeguards
performance of [JCPOA] commitments,” trigger an
agreement and the nuclear Nonproliferation Treaty (NPT).
automatic draft resolution keeping sanctions relief in effect.
(See CRS Report R40094, Iran’s Nuclear Program:
A U.S. veto of this resolution would both reimpose the
Tehran’s Compliance with International Obligations, by
suspended sanctions and end expiration of the conventional
Paul K. Kerr.)
arms and missile-related export restrictions, as well as
Security Council consideration of the Iranian nuclear issue.
https://crsreports.congress.gov
Iran’s Nuclear Program and U.N. Sanctions Reimposition
Whether the United States has the status to invoke
Snapback would also end the process by which the Security
Resolution 2231’s snapback mechanism was under debate.
Council is to end in 2025 its consideration of the Iranian
The JCPOA lacks a withdrawal clause, and no Security
nuclear issue. The council adopted all of the resolutions that
Council resolution has altered the U.S. status as a JCPOA
imposed sanctions on Iran, as well as Resolution 2231,
“participant.” Resolution 2231 is silent on the mechanism’s
under Article 41 of Chapter VII, which enables the Security
status in the event that a P5+1 government ceases
Council to adopt “measures not involving the use of armed
implementing its JCPOA commitments. The United States
force,” including sanctions, “to give effect to its decisions”
neither describes itself nor acts as a JCPOA participant. Not
concerning “threats to the peace, breaches of the peace, and
only does the May 2018 memorandum mentioned above
acts of aggression.” Since adopting Resolution 1737 in
describe a U.S. decision to end its “participation” in the
2006, the council has been considering the Iranian nuclear
agreement, but the United States is also no longer
issue pursuant to Article 41. Iranian officials have touted
performing its JCPOA commitments.
the end of this status, which Resolution 2231 stipulates.
Paragraph 10 of Resolution 2231 names the P5+1 countries
Iranian statements and the JCPOA text indicate that the
as “JCPOA participants.” But it is not clear that
government may stop performing all or some of its JCPOA
“participants” is meant to include a P5+1 government that
commitments if the Security Council extends arms
ceases performing its JCPOA commitments, or if the term
restrictions or invokes snapback. If Iran were to end its
merely identifies the JCPOA participants in July 2015.
JCPOA participation entirely, the government would be
Notably, the agreement describes the P5+1 as “participants”
bound only by its comprehensive safeguards agreement,
when naming those states as members of the JCPOA-
which is indefinite. Iran would not be bound by its
established joint commission. The United States no longer
Additional Protocol, should snapback occur before Iranian
participates in that commission’s activities.
ratification of that agreement.
In an August 20, 2020, letter to Security Council President
In such a scenario, the IAEA would retain its monitoring
Indonesian Ambassador Dian Triansyah Djani, Secretary of
and inspection authority pursuant to Iran’s comprehensive
State Michael Pompeo initiated the snapback process by
safeguards agreement, but the scope of this authority would
notifying the council that Iran “is in significant non-
be narrower. For example, the agency would no longer be
performance” of its JCPOA commitments. This action
able to monitor certain Iranian facilities that do not contain
followed the council’s rejection of a U.S.-sponsored draft
nuclear material but are associated with the government’s
resolution to extend Resolution 2231’s conventional arms-
enrichment program. The IAEA would also retain its
related prohibitions. The letter argued that the Resolution
authority to verify the absence of undeclared nuclear
2231 language gives the United States the right to invoke
material and activities, but the agency would have fewer
snapback. The P4+1 Governments rejected this claim.
means to do so, if Iran’s additional protocol is not in force.
Moreover, Djani explained in an August 21 letter to the
Moreover, Tehran would not be bound by any constraints
council that Pompeo’s letter “has no legal effect.” But
on its enrichment program, which has been the main source
Pompeo stated on September 19 that “the snapback of
of proliferation concern, although Iran would remain bound
previously terminated UN sanctions … became effective”
by its NPT obligations. Significant expansion of Tehran’s
that same day.
enrichment program would likely decrease the amount of
UN Secretary General António Guterres wrote in a
time necessary for Iran to produce enough weapons-grade
September 19 letter that the “majority” of Security Council
highly enriched uranium for use in a nuclear weapon.
members have argued that Pompeo’s letter did not
Prior to the JCPOA, Iran was improving its ability to
constitute the notification necessary for snapback, The
produce fissile material, despite U.N. and other sanctions’
resulting uncertainty, he added, requires the Secretary to
evident success in slowing the nuclear program. At the
refrain from proceeding on the matter. The Security
time, knowledgeable IAEA and U.S. officials observed that
Council could send the issue to the International Court of
IAEA safeguards on Iran’s declared nuclear facilities would
Justice for an advisory opinion, but the council lacks an
likely have detected an Iranian attempt to use them for
independent mechanism to adjudicate these sorts of claims,
producing nuclear weapons. (For more information, see
and council members typically reach political settlements to
CRS Report RL34544, Iran’s Nuclear Program: Status, by
resolve such disputes. The implications of a council failure
Paul K. Kerr.) Nevertheless, Iran’s continuing nuclear
to reach such a settlement in this case are unclear.
program concerned many governments. Indeed, U.S. and
On February 18, 2021, Acting U.S. Ambassador to the UN
Israeli officials at the time planned for a possible attack on
Richard Mills sent a letter to Security Council President UK
Iran’s nuclear program to prevent Tehran from developing a
Ambassador Barbara Woodward “reversing the previous
nuclear weapon. The end of Iranian JCPOA participation
administration’s position on the ... sanctions snapback
could beget a similar situation.
issue,” a State Department official told reporters on the
Iranian officials have indicated that the government might
same day, adding that “the United States is affirming that”
withdraw from the NPT in response to snapback; the treaty
Resolution 2231 “remains in full effect.”
has a withdrawal provision. In this case, Tehran would not
Possible Iranian Responses
be bound by its comprehensive safeguards agreement or its
In addition to reimposing sanctions, snapback would
treaty obligations. Notably, these Iranian officials, echoing
remove other incentives for Iran to continue participating in
a long-standing government position, have stated that
the agreement. These incentives include expiration of the
Tehran would still refrain from producing nuclear weapons.
restrictions on Iranian arms-related imports and exports, as
Paul K. Kerr, Specialist in Nonproliferation
well as missile-related imports described above.
IF11583
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Iran’s Nuclear Program and U.N. Sanctions Reimposition
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