It is silly to presume what those in power can do over night. Nuclear war is no farther away than it was in the 80's.
Now I don't think the world will end that way, I just think it is naive to suggest we are so far away from using nukes. Hopefully I am wrong here.
The difference is to me those that have nukes learned important lesson in the cold war, about detection and so forth. I doubt anyone will be as blatant as to move a nuke to the island of Cuba.
Furthermore, the advances in technology make nukes much smaller, and in some cases obsolete because we have learned other deadly ways to wipe out populations. Ya know?