David Wurmser served as special assistant at the State Department to a diplomat that was appointed  U.S. ambassador to the United Nations by what president?
John R. Bolton John Robert Bolton (born November 20, 1948) is an American lawyer and diplomat who has served in several Republican administrations. Bolton served as the U.S. ambassador to the United Nations from August 2005 until December 2006 as a recess 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 in which a newly elected Democratic Party majority would be taking control in January 2007.
Jerry P. Lanier Jerry P. Lanier is the acting U.S. Ambassador to Sudan he has been in this position since May, 13, 2014. He was the Acting Coordinator for Counterterrorism in the Bureau of Counterterrorism, at the Department of State from December 2012 to February 2014. He is a former Ambassador from the United States of America to the Republic of Uganda.