U.S. Secretary of Defense Chuck Hagel, center, presents a "challenge coin" to a member of the U.S. Army on the tarmac of Kabul airport, March 11, 2013 before boarding a flight to Washin

 

              U.S. Secretary of Defense Chuck Hagel, center, presents a "challenge coin" to a member of the U.S. Army on the tarmac of Kabul airport, March 11, 2013 before boarding a flight to Washin
U.S. Secretary of Defense Chuck Hagel, center, presents a "challenge coin" to a member of the U.S. Army on the tarmac of Kabul airport, March 11, 2013 before boarding a flight to Washington. Hagel encountered political tension with the Afghan president and a series of security problems during his first visit to Afghanistan as Pentagon chief, but he met privately with President Hamid Karzai and says they discussed the key issues. (AP Photo/Jason Reed, Pool)