This week in New York, diplomats from almost every nation will convene for a four-week review of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the most comprehensive nuclear arms agreement in the world.

The stakes could hardly be higher.

Russia, Israel and the United States, all nuclear-armed, are conducting illegal wars of aggression against countries without nuclear weapons. Nuclear-armed India and Pakistan engaged in conflict last year across their disputed border, raising the spectre of nuclear escalation.

In February, the last remaining agreement constraining Russian and US nuclear weapons lapsed, with nothing to replace it. The two countries account for nearly 90% of the world’s nuclear weapons.

And all nine nuclear-armed states are investing vast sums in modernising their arsenals with more capable and dangerous weapons. Deployed nuclear weapons and those on high alert, ready to be launched within minutes, are also rising.

All these developments have brought the Doomsday Clock, which assesses how close the world is to existential catastrophe, closer to midnight than it has ever been since 1947.

The NPT is considered a cornerstone of international law in relation to nuclear weapons and disarmament. It has the widest membership of any arms control agreement, with 190 states. These include five countries that manufactured and exploded nuclear weapons before 1967 – China, France, Russia, the United Kingdom and the United States. All other members do not have nuclear weapons.

North Korea is the only state to have joined the NPT and then renounced it. India, Israel and Pakistan, all nuclear-armed, along with South Sudan, are the only countries........

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