I get letters

In a comment to this post, Adam (who also wins first prize for music suggestions, on volume alone) mentions that the only military justification for the current Anti-ballistic Missile (ABM) plan is the possibility that it would allow the US to use it's nuclear arsenal, thus giving them a non-personnel means of enforcing their empire. That is, an empire without legions.

I think Adam's right, at least I would imagine this has occurred to the people backing ABM, but at the same time I think it's also another item to put on the list of things that ABM could do but won't. For example, ABM could theoretically shoot down an incoming warhead, but probably won't. It could distinguish between a warhead and decoy, but probably won't. It could operate in the rain, but probably won't.

Specifically in this case, I can't imagine a scenario in which the US deploys a even partially-developed ABM system and China, France, the UK, and North Korea don't begin quickly developing cheap countermeasures. The only people who are really going to be threatened by an ABM system are the people who don't have the means to develop the countermeasures, but these are also almost by definition the people without nuclear weapons and ICBM's in the first case.

Really, outside of Iraq, the ABM program is probably the biggest waste of money (in it's current iteration, at least) the US defense industry has going at the moment. The system itself is so expensive, and the enemy responses are so simple and cheap that the US could outspend it's enemies by 100 to 1 and still end up a loser. Now, there are other systems that might work better, but they have their own problems. For example, the developing airborne laser (ABL) project could theoretically hit a missile from a few hundred miles away while the missile was still taking off and therefore relatively slow moving. However, for this to work you need to have your plane within range of the missile silos on short notice - easy to do in the case of Korea, far more problematic for China or Russia.

So, long story short: ABM - big waste of the pretzel moneez.