Ouch. Dubya has ordered that the GPS system be shut down in times of national crisis so that terrorists cannot use it for navigation. What would be the result in such a case? Probably the American troops would shoot up even more of their own people because they no longer know where they're supposed to go. In contrast to the terrorists, who operate in a rather primitive and shirtsleeves manner, the American military is so over-technologized that the soldier can barely function on their own when important technical infrastructure is missing. Well, maybe next time they won't even be able to leave their country in the next war because they no longer know where the country they're supposed to attack actually is and where they themselves are.
At Schneier on Security there is the original article.