The incoming Joe Biden administration stepped in to renew New START for another five years on 3 February, two days before the treaty was due to expire.
New START places limits on the US and Russia in terms of warheads, missiles and launchers that can be used for a nuclear attack on each other’s homelands (‘strategic’ weapons).
Each military can only have 700 ‘deployed’ (operational and armed) methods of attack at any one time.
They can split up that 700 number between three categories: long-range aircraft with nuclear bombs (‘heavy bombers’) and strategic nuclear missiles launched from the ground (ICBMs) or from submarines (SLBMs).
Under New START, each side can only have 1,550 nuclear warheads on deployed delivery systems (each heavy bomber is counted as one warhead), and can only have 800 deployed and non-deployed ICBM launchers, SLBM launchers, and heavy bombers equipped for carrying nuclear bombs.
At the end of February, the British Labour party re-affirmed its intention to keep nuclear weapons if elected, saying this was ‘non-negotiable’.
The shadow defence secretary, John Healey, committed Labour to building four Trident replacement nuclear missile submarines.