Secretary of the Air Force Michael Donley and Air Force Chief of Staff Gen. Norton Schwartz conduct a joint press briefing at the Pentagon in Arlington, Va., Feb. 3, 2012. (DoD photo by Scott M. Ash, U.S. Air Force/Released)

A U.S. Marine Corps MV-22 Osprey aircraft assigned to Marine Medium Tiltrotor Squadron (VMM) 261 (Reinforced) lands aboard the amphibious assault ship USS Iwo Jima (LHD 7) in the Atlantic Ocean Jan. 27, 2012. VMM-261 is part of the 24th Marine Expeditionary Unit and was conducting flight deck certification in support of Bold Alligator 2012. Bold Alligator is a joint and multinational amphibious assault exercise involving several foreign militaries and the U.S. Navy and Marine Corps, designed to execute brigade-sized amphibious assaults against low-to-medium land and maritime threats to improve amphibious core competencies. (DoD photo by Cpl. Michael Petersheim, U.S. Marine Corps/Released)

U.S. Marine Corps Cpl. William Cox, an armorer assigned to the Joint Sustainment Academy Southwest, holds an M4 carbine while providing security as an MV-22 Osprey takes off in support of Enduring Freedom in Zaranj, Nimroz province, Dec. 30, 2011. DoD photo by Cpl. Bryan Nygaard, U.S. Marine Corps (Released)

A U.S. Marine Corps (USMC) F-35 Lightening II aircraft is escorted by two USMC F-18 Hornets as it flies toward Eglin Air Force Base, Fla., Jan. 11, 2012. The USMC's Marine Fighter Attack Training Squadron (VFMAT) 501 received two F-35s. (DoD photo by Staff Sgt. Joely Santiago, U.S. Air Force/Released)

The USCG Healy (WAGB-20) breaks ice around the Russian-flagged tanker Renda 250 miles south of Nome, Alaska, Jan. 6, 2012. The Healy is the Coast Guard's only currently operating polar icebreaker. (DoD photo by Petty Officer 1st Class Sara Francis, U.S. Coast Guard/Released)

New U.S. Soldiers take the oath of enlistment during the opening ceremonies at the U.S. Army All American Bowl in the Alamodome in San Antonio, Texas, Jan. 7, 2012. (DoD photo by Sgt. 1st Class Scott Turner, U.S. Army/Released)

U.S. Sailors assigned to the visit, board, search and seizure team onboard the amphibious dock landing ship USS Pearl Harbor (LSD 52) prepare for a live fire exercise on the flight deck of the ship in the Indian Ocean Jan. 1, 2012. Pearl Harbor was part of the Makin Island Amphibious Readiness Group and was deployed to the U.S. 5th Fleet and U.S. 7th Fleet areas of responsibility. DoD photo by Mass Communication Specialist 2nd Class Jason Behnke, U.S. Navy (Released)