Indeed, except if open war erupts between Ukraine and Russia, I see nothing that goes toward Russia making another annexation move, if the open rebellion doesnt succeed in annexing itself to Russia. In both situations, warheads will not to much.
If it is for the sake of precaution, then all countries can arm themselves, and we can all forget the plans for world disarmement.
Arming a country which is unstable and on the verge of conventional warfare, with nuclear weapons, doesnt seem a good idea to me.
Learn to end your sentences in a polite way.