Then-Army Gen. David Petraeus (left) and Marine Corps Gen. John Allen in August, 2011. Chip Somodevilla/Getty Images hide caption

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U.S. Secretary of Defense Leon Panetta is given a traditional Maori welcome onto the grounds of the Government House on Friday in Auckland, New Zealand. Phil Walter/Getty Images hide caption

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Iran's Supreme Leader Ayatollah Ali Khamenei in 2009. Behrouz Mehri /AFP/Getty Images hide caption

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The American flag, Iraqi flag, and the U.S. Forces Iraq colors are carried during ceremonies in Baghdad today marking the end of the U.S. military mission in Iraq. Pablo Martinez Monsivais/pool/AP hide caption

itoggle caption Pablo Martinez Monsivais/pool/AP