The Bush administration and Congress are in concert on the goal of developing a fleet of unmanned aircraft that can reduce both defense costs and aircrew loses in combat by taking on at least the most dangerous combat missions. Unmanned combat aerial vehicles (UCAVs) will be neither inexpensive enough to be readily expendable nor--at least in early development--capable of performing every combat mission alongside or in lieu of manned sorties. Yet the tremendous potential of such systems in widely recognized, and allies as well as potential of such systems is widely recognized, and allies as well as potential adversaries are moving quickly to mount their own research and development programs. The United States is committed to fielding UCAV capabilities by 2010, principally for the missions of suppression of enemy air defense and deep strike, which are among the highest risk tasks for the Air Force and naval aviation.