Gen. Martin E. Dempsey, Chairman of Joint Chiefs of Staff, in November of 2013. Paul J. Richards /AFP/Getty Images hide caption

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Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey, Secretary of State John Kerry, and Defense Secretary Chuck Hagel testify before the Senate Foreign Relations Committee on Tuesday. Mark Wilson/Getty Images hide caption

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Aug. 13: At Dover Air Force Base in Delaware, the remains of Marine Lance Cpl. Gregory T. Buckley are carried during a dignified transfer. He was killed in a "green on blue" attack. Mark Wilson/Getty Images hide caption

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