FOB SHUKVANI, AFGHANISTAN – MARCH 14: U.S. Secretary of Defense Leon Panetta is greeted by Col. John Shafer (L) with RTC 6 after arriving to greet troops March 14, 2012 at Foward Operating Base Shukvani, Afghanistan. Panetta is also scheduled to meet with President Karzai during his two-day visit to Afghanistan. The trip comes as the Taliban has vowed revenge following this past weekend’s killing spree by a U.S. soldier who is accused of killing 16 civilians in Afghanistan. Most of those killed were children and women. (Photo by Scott Olson/Getty Images)