"Mike Williams" wrote

The cheap solution is to use GPS. But IIRC the US has complete
control over the GPS satellite system. So if you are at war with the
US, you can't count on your GPS working right.

The last I heard, the projected date for the launch of the Galileo Next
Generation Global Navigation Satellite System was some time in 2005, so
after that date there could be an alternative to the American GPS.
However, anyone who's at war with the US is likely to be also disliked
by the Europeans behind Galileo, and might find that they can't get good
readings from either system.

As of this month, Galileo is already subject to US
control/degradation/jamming if necessary.

http://makeashorterlink.com/?W25942BD6
from www.tagesschau.de [bablefish translation]
"Galileo will work on a frequency, which is at any time easily influenceable
for American of military. Without consulting Europe, American armed forces
will be able to switch off the European satellite navigation system Galileo
in crisis and conflicts likewise, as this already happens with the American
global Positioning system (government inspection department). "

Pete