I'd take an educated guess and say Vlad won't start chucking missles as he wants to enjoy the power and wealth he and his billionaire buddies are enjoying in Russia. He may be a self-absorbed authoritarian, but he's he's not stupid. Now as for Trump...
MAD kept the fanatical communists from hurling death and destruction; my fear nowadays is that some nutjob in a dissolving nation will have no qualms. It seems these days there is no sense of impending doom to keep the young 'uns from thinking first. There was always the chance, as I grew up, that today could be one's last day on earth. But it always kept people's, and government's, impulses in check. Now we have numbnuts in the White House encouraging other nations to load up on nukes for self-defence.