To respond to a couple of ideas in this thread, 1)Congress and the american people are likely to allow funding for a national project that will help with the technology needed for theater/tactical/operational defense. 2) Engineers that are working for us are not working for " the bad guys" keep in mid that the threats of tomorrow are not necessarily the threats of today. During the height of the Cold War we would not have been worried about being directly attaked by nations like North Korea or Iraq or who-ever. Also it might be nice if we could offer our allies something in this way. Hey, in 2020 Japan & Taiwan may really need something like this, and we might too. And , I know this will be unpopular,it will be developed so we can sell it as an export, the old miltary-industrial complex. The bad guys got " guns", wouldn't it be nice to at least have access to a " bullet proof vest" ?

The ones who really need this are the Israelis, and they already have their Arrow system deployed. For the rest of us, a nuclear attack would be more easily delivered (by a "rogue state") via a cargo container carried on a ship. This vulnerability has been recognized, as proposals have been made to scan all seaborne cargo containers entering the US for nuclear material. The proposal has been stalled because of the sheer size of the endeavor, and the cost. There are also technical questions as to whether it could actually be done.

Do we need a missile defense system? Maybe. Can we build one that will actually work? Eventually, but maybe not yet. It may be in our national interest to build a missile defense system, IF we can be assured it will work. I'm not at all sure we've demonstrated that yet. Implementing a missile defense that doesn't work as advertised could be worse than not building one at all, since 1) It will cost us significant international good will 2) It will cost quite a lot of money 3) We may find ourselves in a position of relying on it, if we think we have it to rely on. If we think we can afford to piss of some minor nuclear power (e.g China, since our missile defense can absorb their strike) and the missile defense doesn't work properly, it would be unfortunate. I think we should continue to spend on research, but defer a production decision until we've established it will actually work with current technology.

This sort of thing has been going on for three decades. START I limited use of ABMs back then. Looks like a boondoggle to me.

It is an unfortunate fact of 21st century life that we must be prepared to defend ourselves against the foreign and/or domestic crazies of the world. I don't like spending good money for burglar alarms and security doors. But I do. Can we afford not to be as prepared on a national scale? It's better to have and not need than need and not have. Yes,the technology is still shakey and expensive,but new tech stuff always is (right all you V-22 folks?). Yes,the europeans and others don't like it.If we pull this off, some of those same folks will want a piece of the action. Let's keep the R&D going, and if we get it right, let's set up a small-scale system. For the crazies.

It only takes one missile to ruin your whole day. If the system worked well enough to stop one missile and save one cities worth of life, then it is certainly worth it. We don't want to put all our eggs in this basket, but no one will ever trust the system that much anyway. It will be just one more piece of the defense pie, and the research from figuring it all out will help us in many areas just as it did in the space program.

The developement of ICBM technologies by less than stable nations and the possibility of NBC ( nuclear, biological, and chemical) weapons payloads is a reality today. Do we cave into nuclear blackmail when North Korea or some other rogue nation threatens a US city with distruction. What does it matter to someone that is willing to see millions of his people starve or have nothing else to lose if the US retaliates. The only way to protect the US is to deploy an ABM system