There is open evidente that Russia invested in keeping their nukes working. They gave more control over the military to leaders of the nuke program after the Soviet union fell. There are US - Russia nuke inspection treaties (only reciently are they ending) - while the results are classified those with access to them are behaving as if they think they are still working.
They still haven’t managed a successful launch of their new silo missile.
If you were the US inspector, would you tell Russia if you thought their nukes don’t work?
They have plenty of old missiles. And we never know when they are not launching because they want to hide something, or when they launched something to test how a failure happens.
