The Nuclear Ban Treaty: An Overview
Updated January 25, 2021
Since the founding of the United Nations in 1945, the UN General Assembly (UN GA) has cal ed for the
elimination of nuclear weapons. UNGA Resolution A/71/258 (2016)
cal ed on UN member states to
negotiate in 2017 a legal y binding Treaty on the Prohibition of Nuclear Weapons (TPNW), also known as
the nuclear “ban treaty.” Negotiations ended on July 7, 2017, when 122 countries voted to approve the treaty.
Singapore abstained, and the Netherlands voted against it, citing conflicts between the treaty and
its commitments as a member of NATO. The United States and 40 other states did not participate in
negotiations. To date, 84 countries have signed and 50 countries have ratified the treaty. In accordance
with Article 15, the TPNW entered into force
90 days following the 50th ratification on January 22, 2021.
Civil society groups advocated for a nuclear ban, and in 2017, the Nobel Peace Prize
was awarded to the
nongovernmental International Campaign to Abolish Nuclear Weapons (ICAN) for its advocacy role.
Article 1 of the TPNW says that adherents would never “develop, produce, manufacture, otherwise
acquire, possess or stockpile nuclear weapons or other nuclear explosive devices.” This includes a
prohibition on hosting nuclear weapons that are owned or control ed by another state. Nor would states
parties transfer, receive control over, or assist others in developing nuclear weapons. They also would not
use or threaten to use nuclear weapons or other nuclear explosive devices. Article 7 requires states to give
assistance to individuals affected by the use or testing of nuclear weapons and provide for environmental
Article 2 requires a declaration stating whether or not the member state had possessed nuclear weapons in
the past. In addition, Article 4 requires states with nuclear weapons to submit within 60 days a “time-
bound plan for the verified and irreversible destruction of that State Party’s nuclear-weapon program,” to
by the International Atomic Energy Agency (IAEA). Some argue
that would-be treaty
members should devise disarmament details after joining the treaty, because establishing a norm against
nuclear weapons possession and use is the highest priority. Other observers say
it is appropriate that the
treaty does not delineate disarmament steps, as none of those states affected are participating in the
negotiations, and it would be more effective for each state be able to determine its own timeline.
Some critics are concerned that the new treaty would undermine the NPT’s verification system of IAEA
safeguards. The near-universal NPT
, signed in 1968 and entered into force in 1970, commits the five
official y recognized nuclear weapons states (United States, United Kingdom, Russia, France, and China)
to disarmament but is not an outright ban on possession. Nonnuclear weapon NPT states foreswear
nuclear weapons and place nuclear materials and facilities under international safeguards.
The NPT nuclear weapon states, also the five permanent members of the UN Security Council, as wel as
the NATO countries, oppose the TPNW. The United States, UK, and France UN Permanent
Representatives issued a joint press release
stating: “A purported ban on nuclear weapons that does not
address the security concerns that continue to make nuclear deterrence necessary cannot result in the
Prepared for Members and
Committees of Congress
Congressional Research Service
elimination of a single nuclear weapon and wil not enhance any country’s security, nor international
peace and security.” The Trump Administration
actively opposed the TPNW. Press reports have cited an
October 2020 letter
from the United States to TPNW signatories urging them to withdraw support for the
treaty. NATO issued a joint statement
in December reiterating its opposition, saying the TPNW is “at odds
with the existing non-proliferation and disarmament architecture.” The Biden Administration has not yet
stated its policy, and advocates
are pushing for U.S. support for the treaty.
The TPNW highlights a larger debate about how the existing nuclear nonproliferation regime should
evolve, and whether or not the TPNW undermine
s or bolsters the NPT and the Comprehensive Test Ban
Treaty (CTBT). Article 18 of the TPNW says that “[t]he implementation of this Treaty shal not prejudice
obligations undertaken by States Parties with regard to existing or future international agreements, to
which they are parties, where those obligations are consistent with this Treaty.” Proponents
of the TPNW
say that it enhances, rather than contradicts the NPT and is a “wake up cal ” for nuclear weapon states to
make headway on their NPT commitments.
For many treaty advocates, the effort to abolish nuclear weapons stems from strong moral objections.
aim to establish an international norm against the possession and use of nuclear
weapons, which they argue would strengthen nonproliferation and raise awareness of the humanitarian
of developing and using nuclear weapons. Cal s
for such a ban have existed for decades but
have grown in recent years, reflecting the view that nuclear weapon states have been slow
nuclear disarmament under article VI of the NPT and continue to modernize their arsenals. TPNW
advocates point out that while there are international agreements
that ban other categories of weapons of
mass destruction, namely the biological and chemical weapons conventions, there has not been a
prohibition on nuclear weapons until the TPNW.
Some states continue to see nuclear weapons as making a valuable contribution to their security.
Supporters of the ban treaty dismiss nuclear deterrence as a security policy, arguing
that nuclear weapons
can only cause harm to nations and people, and view the risk
of accidental or purposeful use as high while
the weapons exist. Therefore, ban proponents argue, eliminating nuclear weapons is the only way to
prevent nuclear use. Opponents
of the treaty agree that the use of nuclear weapons in war would be
horrific but assert that nuclear deterrence has prevented not only nuclear war, but also major power
conventional conflict, for over 70 years. This view reflects a belief that the best way to prevent nuclear
use is to deter
both nuclear war and major power conflict that could escalate to nuclear war.
Mary Beth D. Nikitin
Specialist in Nonproliferation
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