Russia wouldn’t start one unless they felt their existence was threatened.

I'm really sorry, but a helicopter loaded with green money seems more likely an exit from such a situation.

I hope you do understand that people in Kremlin are degenerate thieves (also mass murderers, of course), they very strongly care for their own lives, but "Russia's existence being threatened" is their last concern. After all, they've contributed so much to that threat that nobody in 1993 would believe it's even possible.

So - no, nukes won't fly because of a threat. They may fly after there's no integral Russian state, then there's a little chance that somebody really delusional in a right way takes control of some nukes. I'm not sure if something like this can happen.