The point is that as the leader of a nuclear power one isn't suppose to joke about certain things -- particularly not a the expense of rival powers one deeply a

The point is that as the leader of a nuclear power one isn't suppose to joke about certain things -- particularly not a the expense of rival powers one deeply anguished relations with (and which one also happens to have come close to full-on doomsday confrontations with, in the not-so-distant past).