So I commented this before, Russia spends the same amount on its nuclear arsenal as the UK, while claiming a far larger arsenal. Even accounting for differences in currency value (so cheaper labour) and assuming Russia has some magical efficiency gains in maintenance its still not enough to even come close to maintaining an arsenal that size. Nukes need the fissile material swapped out every couple of decades or they're just really expensive dirty bombs.

This puts Russia in the position where if they launch a single nuke as a warning there's a genuine chance that it might just fizzle, if that happens it would be crippling to their apperance as a nuclear armed state on the world stage, the embarassment of crossing the ultimate red line with nothing to show for it.

So i guess the answer is the sabre is pretty rusty and it might not snap when rattled but there is a chance it snaps when Putin goes in for a real stab.