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)

U.S. Marines with India Company, Battalion Landing Team, 3rd Battalion, 1st Marine Regiment, listen to directions from company Gunnery Sgt. Jason Walker, left, during a drill aboard amphibious assault ship USS Makin Island (LHD 8) Dec. 4, 2011, in the Pacific Ocean. The team is the ground combat element for the 11th Marine Expeditionary Unit, which was on a seven-month deployment to the western Pacific and Middle East regions. (U.S. Marine Corps photo by Sgt. Elyssa Quesada/Released)

U.S. Air Force Tech. Sgt. John Riccio III, right, and Senior Airman Monica Rivera, center, both with the 177th Fighter Wing, go over operating instructions before performing fabrication work on an F-16C Fighting Falcon aircraft at Bagram Airfield, Afghanistan, Dec. 2, 2011. (U.S. Air Force photo by Tech. Sgt. Matt Hecht/Released)