Plans for GPS-guided bombs to do much of the heavy lifting in a U.S. war on Iraq could be seriously hampered by a $40 device available over the Internet. As reported by the Wall Street Journal, so-called global positioning system “jammers” can interrupt the system’s satellite signal. “At the Paris Air Show in 1999, a Russian company called Aviaconversia demonstrated a 4-watt GPS jammer, weighing about 19 pounds, capable of denying GPS reception for more than 100 miles,” the paper says. “While we do not know the extent of our vulnerability, there is evidence to suggest that GPS jamming can significantly inhibit precision targeting,” says Rep. Joseph Pitts (R., Penn.), co-chairman of Congress’ Electronic Warfare Working Group. So far the only known fix is to boost the GPS signal strength. But without new satellites in place, there’s only so far that approach can go.