For half a century the United States and Russia limited their nuclear arsenals by treaty and let each other's inspectors count the weapons. The last of those treaties expired on 5 February 2026. Each country still has more than five thousand warheads, and nothing now restricts how many it deploys. Both say they want a new arrangement. They disagree on what it should cover, and on whether China, whose smaller arsenal is growing fast, must be part of it.
The wider relationship and each side's full account: The United States and Russia.
Where it stands · September 2026
In September 2026 Russia said there was still time to stop an arms race in space, after an American acknowledgement of work on orbital weapons. The Russian foreign ministry said the United States was considering arming AUKUS submarines with nuclear warheads. A Russian diplomat called instructions on American nuclear tests a threat to the moratorium. The Kremlin said arms control agreements with the United States need preparation.
What the dispute is about
Offence and defence. The treaties rested on a bargain made in 1972: each side limits its missiles and neither builds a shield that could blunt the other's reply. America left that bargain in 2002 and is now building a national missile shield. Russia says any new limit on its weapons depends on limits to that.
Who is counted. Washington wants China included. Beijing refuses while its arsenal is a tenth the size. Moscow answers that then Britain and France must be counted too.
New weapons. Russia has built systems no treaty ever covered: a nuclear-powered cruise missile, a nuclear torpedo, a medium-range missile it has fired at Ukraine. America is modernising every part of its force. Each calls its own programme a response.
