Of course, if you follow this logic to its endpoint, any defensive weapons at all are provocative, since obviously you can use them to protect yourself and your nation if you attack someone.

As for deterrence, I'm not sure I want to bet Seattle that the leader of North Korea won't wake up some night and decide that Daffy Duck, the God of Frustration, has told him to attack the U.S., while he, the great leader, will be protected by the magic of his ancestors from retaliation.

You see, it's not smart to trust a raving lunatic with a gun, just because you can shoot him later if he kills everyone in sight.

Also, considering all the people who are swearing that the best way to deliver a nuke is by rowboat, It's odd that I don't see any rogue nations deciding to stop missile development and build rowboats. How about telling them?

A robust missile defense works just fine against major powers, since it makes a first strike (one designed to take out the retaliatory forces) too uncertain to risk. One thing that never occurred to most people: if a missile defense is so useless, why was the Soviet Union breaking its back trying to keep us from building one? One would think they would have loved to see us waste money on a worthless boondoggle.

And oh, by the way, you have made the best ironclad case for taking out rogue dictators BEFORE they have nuclear weapons that I have ever seen.