Ryan Crocker, who most recently served as ambassador to Pakistan, succeeds Zalmay Kalilzad, who moved to head the U.S. mission at the United Nations.
Crocker was director of governance for the Coalition Provisional Authority in Iraq for six months in 2003. He has also been ambassador to Kuwait, Syria and Lebanon and in other positions in Egypt, Qatar, Iran and Afghanistan.
"I've never met another diplomat who combines his understanding of the Middle East, sense of how best to advance American interests there, and personal toughness and determination," William Burns, the U.S. ambassador to Russia, told The New York Times.
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