Opposition forces infiltrate the base perimeter during a simulated attack against defender forces at Osan Air Base, Korea, on Oct. 25, 1999, as part of Exercise Foal Eagle '99. Foal Eagle '99 is the 38th in a series of regularly scheduled rear area defense field training exercises. The annual exercise is held at a variety of locations throughout the Korean peninsula and involves some 30,000 U.S. military forces. The opposition forces are being played by personnel from the 8th Security Forces Squadron, Kunsan Air Base, Korea, and the Alaska Air National Guard.