Spc. Ben Purvis (center) helps train Afghan troops on how to use mortars in the eastern province of Kunar in June. The top U.S. commander in Afghanistan, Gen. John Allen, points to several factors in the rise of "insider attacks" on American forces. He says relations between U.S. and Afghan troops are good overall. Lucas Jackson/Reuters/Landov hide caption

itoggle caption Lucas Jackson/Reuters/Landov

Gen. Norton Schwartz (shown here in October 2010) is stepping down as the top U.S. Air Force officer. Tim Sloan/AFP/Getty Images hide caption

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U.S. investigators allege that Afghan Gen. Ahmad Zia Yaftali stole tens of millions of dollars' worth of medicine from the Mohammad Daud Khan military hospital in Kabul. He has been removed from that post, but has not been prosecuted. He's shown here at the hospital on Dec. 18, 2010. Altaf Qadri/AP hide caption

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Capt. Jared Larpenteur plans a combat mission at the 82nd Airborne's Delta Company command center in Ghazni province, Afghanistan, earlier this year. Amy Walters/NPR hide caption

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Marines with Echo Company of the Second Battalion, Ninth Marines out of Camp Lejeune, guide their M-ATV, a Mine Resistant Ambush Protected vehicle in to the district government compound in Marjah, Afghanistan. David Gilkey/NPR hide caption

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Bagi Kheyl, in the eastern province of Ghazni, is one of the villages where the 82nd Airborne has been operating as part of a broader effort to drive away the Taliban. Amy Walters/NPR hide caption

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Afghan local police officers wait outside a classroom at a training facility in Marjah. U.S. Marines are training local security forces how to maintain calm in the region. David Gilkey/NPR hide caption

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At Forward Operating Base Payne in Afghanistan's Helmand province, Marine Cpl. Jonathan Odriscoll looks at pictures of his sister on Facebook. Troop access to social media has been both a blessing and curse for the military. Bay Ismoyo/AFP/Getty Images hide caption

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A Marine Corps team carries the remains of Marine Sgt. J.P. Huling, 25, of West Chester, Ohio, at Dover Air Force Base, Del., on May 9. Huling was killed three days earlier by an Afghan soldier in southern Afghanistan, one of a growing number of such shootings. Cliff Owen/AP hide caption

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In Afghanistan, American troops are pushing Afghans to take charge. David Gilkey/NPR hide caption

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U.S. troops are training Afghan soldiers to take more responsibility in the war against the Taliban. But the Afghans still depend heavily on the Americans. Here, an Afghan solider fills up gas cans with diesel fuel from a U.S. Army tanker in southern Afghanistan. David Gilkey/NPR hide caption

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Wounded Warrior Battalions have been set up to help troops returning from combat recover from their injuries. But recent Pentagon reviews have found a pattern of overmedication in such battalions. Here, Marines assigned to Wounded Warrior Battalion East at Walter Reed National Military Medical Center in Bethesda, Md., graduate from a training course in January. Capt. Jill L. Wolf hide caption

itoggle caption Capt. Jill L. Wolf

The Marines' most senior officers — including top commander Gen. James Amos (shown here in 2011 in Afghanistan's Helmand province) — are weighing in on recent incidents involving misconduct by troops serving in Afghanistan. Bay Ismoyo/AFP/Getty Images hide caption

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