Nuclear treaties and arms control
For fifty years, treaties capped the arsenals and froze the club. In 2026 the last US-Russian ceiling is gone — here is what remains of the architecture, and who is bound by what.
The four pillars
The foundation. The NPT recognizes five nuclear-weapon states — those that had tested by 1967: the US, USSR/Russia, UK, France and China — and commits everyone else to renounce the bomb in exchange for civil nuclear cooperation, under IAEA safeguards. Article VI commits the five to pursue disarmament; that promise anchors most of today's disputes. With 191 parties it is the most-subscribed arms treaty in history. India, Pakistan and Israel never joined and built arsenals outside it; North Korea joined, cheated, and withdrew in 2003 — the only state ever to leave.
Bans all nuclear explosions, everywhere, forever — and has never entered into force, because it requires ratification by 44 named states and eight still withhold it, including the United States and China (signed, never ratified) and now Russia, which revoked its ratification in 2023 to "mirror" Washington. Its monitoring network of over 300 stations works anyway, and a de facto moratorium holds: apart from North Korea, no state has tested since 1998. Renewed activity at the US, Russian and Chinese test sites keeps the question of a return to testing open.
The abolitionists' answer to Article VI's unkept promise. In force since January 2021, the TPNW bans developing, possessing, stationing or threatening to use nuclear weapons — including hosting someone else's, which is why every NATO member rejects it. More than 70 states are parties, mostly from the Global South; South Africa, the only country to have disarmed a real arsenal, is among them. No nuclear-armed state has joined, so its force is normative: it makes the weapons' illegitimacy, not their absence, the international standard.
From SALT I (1972) through START, SORT and finally New START (2011), Washington and Moscow spent five decades negotiating verifiable caps on their strategic forces — shrinking deployed arsenals from tens of thousands of warheads to 1,550 each, checked by on-site inspections. That era is over: Russia suspended participation in 2023, inspections never resumed, and New START expired on 5 February 2026 with no successor. Moscow says it will observe the old ceilings voluntarily for now; Washington speaks of a "modernized" treaty. For the first time since 1972, nothing legally limits the two largest arsenals.
Who is bound by what
| Country | NPT | CTBT | TPNW |
|---|---|---|---|
| 🇷🇺 Russia | Nuclear-weapon state | Ratification revoked 2023 | Not party |
| 🇺🇸 United States | Nuclear-weapon state | Signed, not ratified | Not party |
| 🇨🇳 China | Nuclear-weapon state | Signed, not ratified | Not party |
| 🇫🇷 France | Nuclear-weapon state | Ratified 1998 | Not party |
| 🇬🇧 United Kingdom | Nuclear-weapon state | Ratified 1998 | Not party |
| 🇮🇳 India | Never joined | Not signed, test moratorium | Not party |
| 🇵🇰 Pakistan | Never joined | Not signed | Not party |
| 🇮🇱 Israel | Never joined | Signed, not ratified | Not party |
| 🇰🇵 North Korea | Withdrew 2003 | Not signed | Not party |
| 🇮🇷 Iran | Party, safeguards disputed | Signed, not ratified | Not party |
| 🇿🇦 South Africa | Joined 1991 after disarming | Ratified | State party |
| 🇧🇪 Belgium | Non-nuclear-weapon state | Ratified | Not party |
| 🇧🇾 Belarus | Non-nuclear-weapon state | Ratified | Not party |
| 🇩🇪 Germany | Non-nuclear-weapon state | Ratified | Not party |
| 🇮🇹 Italy | Non-nuclear-weapon state | Ratified | Not party |
| 🇳🇱 Netherlands | Non-nuclear-weapon state | Ratified | Voted against, 2017 |
| 🇹🇷 Turkey | Non-nuclear-weapon state | Ratified | Not party |
Frequently Asked Questions
Is any treaty still limiting US and Russian nuclear weapons?
No. New START, the last treaty capping deployed strategic warheads, expired on 5 February 2026 without a successor — the first time since 1972 that the two largest arsenals face no negotiated ceiling. Russia has said it will voluntarily observe the old limits for now, and Washington has spoken of seeking a modernized agreement, but nothing is legally binding.
What does the NPT actually do?
The 1968 Non-Proliferation Treaty froze the club: the five states that had tested by 1967 are recognized as nuclear-weapon states, everyone else renounces the bomb in exchange for civil nuclear cooperation and a promise of eventual disarmament. With 191 parties it is the most-subscribed arms treaty in history; India, Pakistan and Israel never joined, and North Korea withdrew in 2003.
Does the Treaty on the Prohibition of Nuclear Weapons ban the bomb?
For its parties, yes — the TPNW, in force since 2021, prohibits developing, possessing, hosting or threatening to use nuclear weapons. But no nuclear-armed state and no NATO member has joined, so its effect is normative rather than operational: it codifies the position of the states that want the weapons outlawed entirely.
Is nuclear testing banned?
In practice but not in law. The Comprehensive Nuclear-Test-Ban Treaty was opened for signature in 1996 and has never entered into force, because key states — including the US and China — signed but never ratified, and Russia revoked its ratification in 2023. A de facto moratorium holds: North Korea is the only state to have tested this century.