From Peace Corps Wiki
John W. Limbert is the charge d'affaires of the United States embassy in Khartoum, Sudan. Previously he was the ambassador to Mauritania from 2000-2003.
Limbert was born in Washington, D.C. where he attended public school. After high school he went to study at Harvard University, receiving a B.A., M.A. along with a Ph.D. in History and Middle Eastern Studies. Before joining the U.S. Foreign Service, he taught in Iran, both as a Peace Corps Volunteer (1964-66) and as a faculty member at Pahlavi University from 1969 to 1972, and speaks Persian fluently. Limbert worked at the American embassy in Iran when it was overrun by students, and spent 9 months in solitary confinement  during the Iran hostage crisis.