International Nuclear Non-Proliferation Framework

The international nuclear non-proliferation framework is a set of treaties, safeguards and verification mechanisms aimed at preventing the spread of nuclear weapons. It also supports disarmament efforts and allows the peaceful use of nuclear energy under international oversight.

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT)

• Adoption and pillars: Opened for signature in 1968 and entered into force in 1970, the NPT rests on three pillars: non-proliferation, disarmament and the peaceful use of nuclear energy.
• State categories: The treaty recognises Nuclear Weapon States (NWS) as those that manufactured and exploded a nuclear weapon before 1 January 1967. These are the US, Russia, the UK, France and China.
• Non-Nuclear Weapon States (NNWS): Other parties are treated as NNWS and accept obligations not to acquire nuclear weapons.
• Safeguards under Article III: NNWS must accept safeguards agreements with the International Atomic Energy Agency (IAEA) to verify that nuclear materials are not diverted from peaceful uses to weapons programmes.
• Non-signatories and withdrawal: India, Pakistan, Israel and South Sudan have never signed the NPT, while North Korea signed the treaty and announced withdrawal in 2003.

CTBT and TPNW

• CTBT purpose: The Comprehensive Nuclear-Test-Ban Treaty seeks to end all nuclear explosion testing, including for weapon development.
• Annex 2 requirement: The CTBT can enter into force only after all 44 Annex 2 states ratify it.
• Annex 2 holdouts: The states yet to ratify include China, Egypt, India, Iran, Israel, North Korea, Pakistan, the US and Russia.
• TPNW significance: The Treaty on the Prohibition of Nuclear Weapons imposes a categorical ban on nuclear weapons for its parties, unlike the NPT.

Bilateral Arms Control and Regional Safeguards

• US-Russia controls: Bilateral arms control agreements between the US and Russia long served as the main constraint on strategic nuclear forces.
• New START: Signed in 2010 and extended in 2021, New START capped deployed strategic warheads at 1,550 and launchers/bombers at 800 before its expiration on 5 February 2026.
• Legal gap: After New START expired, the US and Russia were left without legally binding limits on strategic nuclear weapons.
• AUKUS and safeguards: Under AUKUS, Australia is negotiating with the IAEA under Article 14 of its Comprehensive Safeguards Agreement for verification arrangements relating to its conventionally armed, nuclear-powered submarine programme.

The International Atomic Energy Agency (IAEA)

• Establishment and role: The IAEA was established in 1957 as an autonomous organisation and functions as the world’s nuclear inspectorate.
• Reporting line: It reports to both the United Nations General Assembly and the Security Council.
• Verification function: The agency checks whether nuclear materials are being used only for peaceful purposes, in line with safeguards agreements.
• Ukraine facility monitoring: At the Zaporizhzhya Nuclear Power Plant, the IAEA has brokered local ceasefires to support repairs to damaged off-site power lines.
• Iran inspections: The IAEA temporarily suspended in-field verification activities in Iran in February 2026 and later resumed a routine inspection at the Bushehr Nuclear Power Plant in late May 2026.

Key Prelims Takeaways

• NPT structure: The treaty is built on non-proliferation, disarmament and peaceful use of nuclear energy.
• Recognised nuclear states: The NPT recognises five Nuclear Weapon States: the US, Russia, the UK, France and China.
• CTBT entry into force: All 44 Annex 2 states must ratify the CTBT before it can come into force.
• TPNW position: The TPNW bans nuclear weapons completely for its parties, without exceptions.
• IAEA safeguards: Under Article III of the NPT, NNWS must accept IAEA safeguards to ensure peaceful use of nuclear material.
• New START significance: New START was the last major legally binding cap on US-Russia strategic nuclear forces before it expired on 5 February 2026.
• AUKUS and Article 14: Australia’s nuclear-powered submarine arrangements are being discussed within the safeguards framework of Article 14 of its Comprehensive Safeguards Agreement.