I just can't understand the Democrats' reflexive knee-jerk urge to oppose weapons systems. Its a stance that would make sense coming from a pacifist. This NYT article documents the criticisms Democrats are levelling at missile defense at the moment. None of them stand up to scrutiny:

Bush is insisting on implementing a national defense system for election-year reasons. This ignores the fact that Bush called for a functional missile defense system by 2004 back in '99 on the campaign trail. Guess what? Its 2004.

There is no imminent threat we need to protect against immediately. The whole point of a missile defense system is that if terrorists manage to get ahold of a nuclear bomb + a means to launch it, we will have a means of defense. Just because no terrorists have a nuclear bomb at the moment does not mean that we are safe. Oh, and by the way, North Korea is in the process of developing a missile that can reach the American mainland.

Missile defense costs money. 10 billion dollars per year out of 2.4 trillion dollar budget. Not terribly much. Kerry, for example, is proposing to roll back the Bush tax cut to the tune of 900 billion dollars over the next decade or so. Clearly, missile defense is nothing we can't afford.

If we implement the system now, it won't work perfectly. So what? We can add more interceptors and improve the probability of a hit as we go along. There's no reason why we can't implement a less-than-perfect system now which would provide some measure of protection, and improve it once its built.

Update: More on the missile-defense-by-2004 issue -- an op-ed written in '99 by the defense officials from the Carter/Clinton administrations in Foreign Policy suggests:

As soon as possible, forward-deploy current systems that are configured to provide some capability against North Korean ballistic missiles. Deployment of an aegis cruiser equipped with an existing missile and aerodynamic kill vehicle off the coast of North Korea can provide modest capability for a boost-phase intercept of the Taepo-Dong missile. This capability could be available well before the initial operational capability of the NMD system in 2005.

Another update: This article, written in '99, details some of the North Korean efforts to develop ICBM's. I haven't read anything about North Korean misiles lately so its difficult to estimate that how much progress has been made in the last 5 years. Incidentally, Kim Jong Il is quoted in this piece as saying: If we can develop this we have nothing to fear. Even the American Bastards won't be able to bother us. Whether we live or die, we must quickly develop the Hwasong 6. Hwasong-6 is the name of one of the missiles under developement.

Final update: On the other hand, a recent Slate piece by Fred Kaplan argues that the sucessful missile defense tests were practically rigged.