Admiral Mike Mullen, Secretary Of Defense Leon Panetta And Vice President Joe Biden Pause

From left, Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, Secretary of Defense Leon Panetta and Vice President Joe Biden pause for a moment of silence during a ceremonty at the Pentagon, in Arlington, Va., on the tenth anniversary of the 9/11 attacks against the United States, Sunday, Sept. 11, 2011. (Official White House Photo by David Lienemann)