Samizdata has the scoop:
"It is now evident that by reserving a frequency in close proximity to the frequency used by code M, the Europeans have put themselves in a position to veto the effective use of GPS by America's armed forces. They believe that once they have begun transmitting on this frequency, the US will have no choice but to ask their permission before conducting any GPS supported military operations. This, in effect, means all US operations anywhere in the world. For example, in case of a North Korean attack, the US would have to ask the EU for permission before it could begin flying close air support missions against invading North Korean troops . This would give the EU enormous leverage whenever the EU wanted the US to concede something in the Middle East or elsewhere."That's why they invented the expression "sand 'em out of orbit".
