ARLINGTON, VA – JUNE 30: United States Secretary of Defense Robert Gates (L) and President Barack Obama cover their hearts during the playing of the Star Spangled Banner during Gates’ Armed Forces Farewell Tribute on the River Parade Field at the Pentagon June 30, 2011 in Arlington, Virginia. Appointed by former President George W. Bush in 2006, Gates is credited with many landmark decisions and actions, including the turning around of the war in Iraq by directing the troop surge, the repeal of the don’t ask, don’t tell policy, the handling of the Walter Reed Army Medical Center neglect scandal and a huge shift toward fiscal restraint in military spending. Gates will be succeeded as head of the Pentagon by CIA Director Leon Panetta. (Photo by Chip Somodevilla/Getty Images)