The question at that point is whether the world's latest little dictator will be satisfied with Ukraine (and perhaps former Soviet possessions in Eastern Europe like Poland, Estonia, Latvia, Lithuania, etc.) or whether he will proceed to invade Germany and France. If he does invade any country besides Ukraine it would obligate a NATO response but I'm unsure if Obama would follow treaty obligations (direct war with Russia) or if it would be the effective end of NATO. Anyway there's a ceasefire until Mar 21, so the nuclear holocaust will likely not occur until at least this weekend.