Witnesses testifying before the Senate Armed Services Committee on Capitol Hill in Washington, Wednesday, April 14, 2010, about U.S. policy toward Iran's nuclear program are, from left to right: Undersecretary of Defense for Policy Michele Flournoy, Undersecretary of State for Political Affairs William Burns, Marine General James Cartwright, the vice chairman of the Joint Chiefs of Staff, and Lt. Gen. Ronald Burgess, head of the Defense Intelligence Agency. (AP Photo/J. Scott Applewhite)
** FILE ** Marine Corps Commandant Gen. James Amos, right, accompanied by Joint Chiefs Vice Chairman Marine Corps Gen. James Cartwright, testifies on Capitol Hill in Washington on Dec. 3, 2010. (Associated Press)
Joint Chief Vice Chairman Gen. James E. Cartwright, right, accompanied by Defense Undersecretary for Personnel and Readiness Clifford Stanley, conduct a media briefing at the Pentagon to discuss the progress of the "Don't Ask, Don't Tell" repeal implementation effort. (AP Photo/Pablo Martinez Monsivais)
President Obama discusses the Afghanistan-Pakistan annual review Thursday as (from left) Defense Secretary Robert M. Gates, Vice President Joseph R. Biden Jr., Secretary of State Hillary Rodham Clinton and Marine Gen. James Cartwright look on.
** FILE ** President Obama (center), accompanied by (from left) Defense Secretary Robert M. Gates, Vice President Joseph R. Biden Jr., Secretary of State Hillary Rodham Clinton and Marine Gen. James Cartwright, speaks about the Afghanistan-Pakistan annual review on Thursday, Dec. 16, 2010, at the White House in Washington. (AP Photo/Susan Walsh)
Joint Chiefs Vice Chairman Gen. James Cartwright outlines the Defense Department's fiscal year 2010 budget request during a news conference at the Pentagon in Arlington, Virginia, on April 6, 2009. (UPI Photo/Roger L. Wollenberg)