Valiant Shield
An F-15 aircraft, assigned to the U.S. Air Force's 18th Wing, flies over Guam in support of Exercise Valiant Shield. Valiant Shield is a training exercise with a focus on integration and proficiency of the U.S. Army, Navy, Air Force and Marine Corps through engaging units at sea, in the air, on land, and in cyberspace in response to the mission. (U.S. Navy photo by Mass Communication Specialist 2nd Class Chelsy Alamina)