Many of the technologies were proven, aside from the fatal hang-up with the tanks.

NMD appears to me to be all about Rumsfeld's emphasis on space assets. This emphasis is needed and long overdue. In my opinion, however, NMD is a completely misguided approach. But I will concede that Rumsfeld and the Pentagon need to find some way to justify a greater military presence in space, and that NMD may be the way to get the ball rolling.

I think we will see X-33 come back later, though perhaps in a different somewhat modified form. Because NMD has run into some trouble, Rumsfeld and the JCS may be adopting a more conservative strategy. Dropping X-33 may be a compromise in the short-term for gains in the long-term. If the Pentagon can get its NMD, then it can later call for either a revival of the X-33 or the development of an X-33 successor, which would of course be justified by the existence of the NMD program.

This reminds me of the whole chicken-and-egg paradox NASA ran into decades ago over the Shuttle. How to justify the Shuttle without a Space Station as its destination? How to justify a Space Station without some reliable method for getting back and forth? Looks to me like the Pentagon now finds itself in the same position NASA once occupied.

Let's hope it never finds itself where NASA is now, unable to find a successor to an aging Shuttle fleet, and burdened with a white elephant fiasco in orbit.