Darryl St. George, a Navy corpsman with Weapons Company of the 2nd Battalion, 8th Marines out of Camp Lejeune, N.C., reads a book as the sun rises over a temporary base nicknamed "Patrol Base Suc" in Helmand province, southern Afghanistan. David Gilkey/NPR hide caption

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A Marine walks along a mud wall while conducting a search and clearing operation in Afghanistan's Helmand province, as the dust from a wheat thrashing machine falls like snow. David Gilkey/NPR hide caption

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Marine Lance Cpl. Andrew Zemore, 23, from Fredericksburg, Va., is a self-described troublemaker who liked to party too much. Zemore said he fell into the Marine Corps and now is on a Explosives Ordinance Disposal team, searching out bombs with a hand-held metal detector. David Gilkey/NPR hide caption

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Afghan National Army troops take a break while on a joint patrol and clearing operation with Butcher Troop, part of the U.S. Army's 1st Infantry Division, in eastern Afghanistan. David Gilkey/NPR/Redux hide caption

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Isutalah of the Interim Security for Critical Infrastructure force on foot patrol in northern Marjah with Marines of Golf Company, 2nd Battalion, 8th Regiment. David Gilkey/NPR hide caption

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Sgt. Joseph Garrison with Fox Company, 2nd Battalion, 8th Marine Regiment, runs through the desert near Camp Leatherneck during a drill in June 2009. Garrison was killed while on his fourth combat deployment to Afghanistan in June 2011, when he was struck by a homemade bomb in Marjah. David Gilkey/NPR hide caption

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Blackwater security contractors are seen in a helicopter in Baghdad in 2007. The company changed its name to Xe in 2009, amid controversy surrounding the killing of 17 Iraqi civilians in 2007. Khalid Mohammed/AP hide caption

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A Pakistani shepherd in Abbottabad walks past the hideout of al-Qaida leader Osama bin Laden, who was killed in a U.S.-led ground operation early Monday. Aamir Qureshi/AFP/Getty Images hide caption

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The aircraft carrier USS Enterprise, shown departing from Naval Station Norfolk on Jan. 13, is now in the Red Sea, with its dozens of warplanes, waiting to see if it's needed for any Libyan operation. U.S. Navy/Getty Images hide caption

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President Ronald Reagan gestures during a news conference at the White House in January 1986, when he said there was "irrefutable evidence" that Libyan leader Moammar Gadhafi was involved in airport attacks in Rome and Vienna in December 1985. Scott Stewart/AP hide caption

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