Nuclear Treaties & Arms-Control Agreements: 1945–2026

  Below is an exam-oriented chronological order of the major nuclear treaties and nuclear arms-control agreements from 1945 to 2026. I have included the major global treaties as well as the principal U.S.–Soviet/Russian strategic arms-control agreements.

Nuclear Treaties & Arms-Control Agreements: 1945–2026

Year Treaty / Agreement Main significance

1945 UN Charter / Beginning of Nuclear Age Hiroshima and Nagasaki marked the beginning of the nuclear age.

1946 UN Atomic Energy Commission – First UN Resolution on Nuclear Energy First major UN initiative toward international control of atomic energy and elimination of atomic weapons. 

1953 Atoms for Peace Proposal U.S. proposal promoting peaceful nuclear energy under international safeguards. 

1959 Antarctic Treaty Prohibited nuclear explosions and disposal of radioactive waste in Antarctica.

1963 Partial Test Ban Treaty (PTBT) Banned nuclear tests in the atmosphere, outer space and underwater. 

1967 Treaty of Tlatelolco Created a nuclear-weapon-free zone in Latin America and the Caribbean.

1967 Outer Space Treaty Prohibited placing nuclear weapons and other WMDs in orbit or on celestial bodies.

1968 Nuclear Non-Proliferation Treaty (NPT) Prevented proliferation, promoted peaceful nuclear energy and committed parties to nuclear disarmament. It entered into force in 1970. 

1971 Seabed Arms Control Treaty Prohibited placement of nuclear weapons and other WMDs on the seabed beyond coastal zones.

1972 SALT I First major U.S.–Soviet strategic arms limitation agreement.

1972 Anti-Ballistic Missile (ABM) Treaty Limited U.S. and Soviet strategic missile-defence systems.

1974 Threshold Test Ban Treaty (TTBT) Limited the yield of underground nuclear tests to 150 kilotons.

1976 Peaceful Nuclear Explosions Treaty (PNET) Regulated underground nuclear explosions conducted for purported peaceful purposes.

1979 SALT II Sought further limits on U.S. and Soviet strategic nuclear weapons.

1987 INF Treaty Eliminated U.S. and Soviet ground-launched ballistic and cruise missiles with ranges of 500–5,500 km.

1991 START I Major reduction and limitation of U.S. and Soviet strategic nuclear arsenals.

1992 Lisbon Protocol Established arrangements for former Soviet republics to join the START framework and ultimately become non-nuclear-weapon states.

1993 START II Sought further reductions in U.S. and Russian strategic nuclear weapons; it never entered into force.

1996 Comprehensive Nuclear-Test-Ban Treaty (CTBT) Prohibited all nuclear explosions; still has not entered into force. 

2002 SORT / Moscow Treaty U.S. and Russia agreed to reduce operationally deployed strategic nuclear warheads.

2010 New START Limited U.S. and Russian deployed strategic nuclear warheads to 1,550 each and strategic delivery systems to 700 deployed systems. 

2017 Treaty on the Prohibition of Nuclear Weapons (TPNW) Prohibits nuclear weapons under international law for its parties; entered into force in 2021. 

2021 New START Extension U.S. and Russia extended New START for five years, through February 2026. 

2026 New START Expired New START expired on 5 February 2026, ending the treaty's binding limits on U.S. and Russian strategic nuclear arsenals. 

2026 NPT Review Conference The 11th NPT Review Conference was scheduled for 2026 to examine implementation of the NPT. 

⭐ Most Important Sequence for Competitive Exams

Memorise this sequence:

PTBT (1963)

↓

Tlatelolco + Outer Space Treaty (1967)

↓

NPT (1968)

↓

SALT I + ABM Treaty (1972)

↓

TTBT (1974)

↓

SALT II (1979)

↓

INF Treaty (1987)

↓

START I (1991)

↓

START II (1993)

↓

CTBT (1996)

↓

SORT/Moscow Treaty (2002)

↓

New START (2010)

↓

TPNW (2017)

↓

New START extended (2021)

↓

New START expired (2026)

Important distinctions

NPT vs CTBT vs TPNW

NPT (1968): focuses on non-proliferation, peaceful nuclear cooperation and disarmament. 

CTBT (1996): focuses on banning nuclear explosions, but it has not entered into force. 

TPNW (2017): goes further by prohibiting nuclear weapons for states that are parties to it; it entered into force on 22 January 2021. 

New START (2010): concerned U.S.–Russia strategic nuclear arsenals and expired on 5 February 2026. 

Easy memory chain:

63 → 67 → 68 → 72 → 74 → 79 → 87 → 91 → 93 → 96 → 02 → 10 → 17 → 21 → 26

Sources: United Nations, UN Treaty Collection, UN Office for Disarmament Affairs, and official NPT documentation.