U.S. servicemembers enrolled at Marine Corps Command and Staff College listen to Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, Quantico, Va., April 30, 2010. DoD photo by U.S. Navy Petty Officer 1st Class Chad McNeeley

U.S. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, arrives at the Marine Corps Command and Staff College in Quantico, Va., April 30, 2010. DoD photo by U.S. Navy Petty Officer 1st Class Chad McNeeley

U.S. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, addresses students attending Marine Corps Command and Staff College in Quantico, Va., on April 30, 2010. DoD photo by U.S. Navy Petty Officer 1st Class Chad McNeeley

U.S. Airman 1st Class Claudia Segovia boards a Boeing 737 bound for Bagram Airfield, Afghanistan, April 29, 2010, Segovia is assigned to the 492nd Fighter Squadron at Royal Air Force Lakenheath, England. U.S. Air Force photo by Airman 1st Class Eboni Knox

Three A-10C Thunderbolt IIs fly in formation beside a KC-135 Stratotanker, April 27, 2010, during an aerial refueling mission over Southern Arizona. The A-10 pilots are assigned to the 358th Fighter Squadron at Davis-Monthan Air Force Base, Ariz. U.S. Air Force photo by Airman Jerilyn Quintanilla

A U.S. Air Force C-130 Hercules cargo aircraft is prepared for loading with water during training on Modular Airborne Firefighting Systems in Greenville, S.C., April 27, 2010. The airborne system is inserted into H and J model C-130s to convert them into air tankers capable of carrying 3,000 gallons of fire retardant or water that can be discharged in less than five seconds. U.S. Air Force photo by Staff Sgt. Michael B. Keller

U.S. Air Force Senior Airman Tyler Brunner checks M-4 carbine rifles in the armory on Ellsworth Air Force Base, S.D., April 27, 2010. Brunner is a staff armory airman assigned to the 28th Security Forces Squadron. U.S. Air Force photo by Airman 1st Class Anthony Sanchelli

U.S. Air Force pararescuemen assemble a PRC-152 radio during an earthquake-response exercise scenario as part of Angel Thunder 2010, Southern Arizona, April 19, 2010. The airmen are assigned to the 38th Rescue Squadron. U.S. Air Force photo by Airman Jerilyn Quintanilla