Former Defense Secretary Donald H. Rumsfeld (left) and former President George W. Bush pause for a moment of silence after laying a wreath at the Pentagon on Saturday, Sept. 10, 2011, in commemoration of the 10th anniversary of the Sept. 11 attacks. (AP Photo/Charles Dharapak)
Vice President Joseph R. Biden Jr. (right), Defense Secretary Leon E. Panetta (center) and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, participate in a ceremony on Sunday, Sept. 11, 2011, at the Pentagon to honor victims of the Sept. 11 attacks. (AP Photo/Charles Dharapak)
Beatriz "Pat" Hymel Lipinski, who was widowed when her husband Lt. Col. Robert J. Hymel was killed at the Pentagon, searches the attic for a photograph of him at her home. She married Ed Lipinski in the years since the attack and they live in Mathews, Va. (Rod Lamkey Jr./The Washington Times)
Red roses sit beneath the bench honoring Navy Cmdr. William H. Donovan at the National 9/11 Pentagon Memorial in Arlington. The memorial is dedicated to the 184 people who were killed when a hijacked plane was flown into the Pentagon on Sept. 11, 2001. (Barbara L. Salisbury/The Washington Times)
Ashton Carter, undersecretary of defense for acquisition, technology and logistics, discusses a mine-resistant ambush-protected armored fighting vehicle at the Pentagon. President Obama wants to promote the weapons buyer, but Mr. Carter has done some consulting work for the defense industry. (Associated Press)
President Obama (center) and Adm. Mike Mullen (right), chairman of the Joint Chiefs of Staff, sit with outgoing Defense Secretary Robert M. Gates during a tribute to Mr. Gates on June 30, 2011, at the Pentagon. (Associated Press)
CIA Director Leon E. Panetta is poised to move to the Pentagon following unanimous Senate approval Tuesday of his nomination to head the Defense Department. He begins his new job July 1.
Law enforcement work near the Pentagon after a suspicious vehicle forced multiple road closures Friday, June 17, 2011 in Arlington, Va. One person was taken into custody early Friday morning in Arlington National Cemetery after it closed. "This is an unfolding situation," said U.S. Park Police. Police were investigating a suspicious package in the man's car parked in the bushes near the Pentagon's North Parking lot. (AP Photo/Alex Brandon)
Law enforcement work near the Pentagon after a suspicious vehicle forced multiple road closures Friday, June 17, 2011 in Arlington, Va. In a situation that is still unfolding, officials say one man is in custody after they found his car, parked in the bushes near the Pentagon. The car contained material that appears to be ammonium nitrate, spent 9 mm shells and written materials stating "al Qaeda Taliban rules." (AP Photo/Alex Brandon)
Sarah Palin, with her daughter Piper (center), answers a reporter's question at the beginning of the Rolling Thunder motorycycle ride at the Pentagon on Sunday. She smiled broadly when many in the crowd urged her to run for the presidency.
Former Alaska Gov. Sarah Palin (second from right), the 2008 GOP vice presidential nominee, gives a thumbs up from the back seat of a motorcycle at the beginning of Rolling Thunder at the Pentagon in suburban Washington on Sunday, May 29, 2011. (AP Photo/Alex Brandon)
Secretary of Defense Robert M. Gates (left) and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, speak to the press at the Pentagon outside Washington on Wednesday, May 18, 2011. (AP Photo/Alex Brandon)