Before WWII started if the allies would have shown some guts to smack down Hitler in 1936, he would have been stopped. We now have the same situation with Iran. The window to exercise any power is slowly slaming shut. Once they have a nuke & a delivery system the whole ball game will change. We know we can defeat N.Korea,but the economic havoc on the world economy with the destruction of S.Korea will be much greater than the military effect of the north's military. The same will hold true when Iran becomes nuclear. The major difference is deterance is only effective against rational nations. It is meaningless against religious fanatics.