John Robert Bolton (born November 20, 1948) is an American lawyer and diplomat who has served in several Republicanadministrations. Bolton served as the U.S. ambassador to the United Nations from August 2005 until December 2006 as arecess appointee by President George W. Bush.He resigned in December 2006, when the recess appointment would have otherwise ended,because he was unlikely to win confirmation from the Senate which was then controlled by Democratic Party since January 2007.