Nuclear treaties and arms control

The multilateral treaties set the rules of the club; the bilateral ones capped the two arsenals that hold almost all the world's warheads. The first set still stands, if strained. The second has unravelled one treaty at a time since 2002, and with New START's expiry nothing of it is left.

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. Its 2026 Review Conference (27 April to 22 May) ended without a final document, the third failure in a row after 2015 and 2022.

Bans all nuclear explosions, everywhere, forever — and has never entered into force, because it requires ratification by 44 named states and nine 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, whose last test was in 2017, no state has acknowledged a test since 1998. The question is open again: on 30 October 2025 the US president ordered testing "on an equal basis", on 5 November Russia's president ordered proposals for a possible test, and on 6 February 2026 Washington accused China of a secret low-yield test at Lop Nur in 2020, which Beijing calls unfounded.

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.

It has 75 states parties as of September 2026, mostly from the Global South, and holds its first Review Conference from 30 November 2026; 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 (2010), 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 declared the parties no longer bound and says it will hold its forces at the old levels only as long as Washington does; Washington wants a "modernized" treaty that also covers China. For the first time since 1972, nothing legally limits the two largest arsenals.