Thomas Shannon received a B.A. in government and philosophy from the College of William and Mary and a Ph.D. in politics from Oxford University (UK). He started his foreign service career as a political officer at the U.S. Embassy in Guatemala in 1984.   Shannon served at various embassies from Johannesburg to Caracas until 1999, when he became Director for Inter-American Affairs at the National Security Council. In 2000, he became U.S. Deputy Permanent Representative to the OAS, followed by positions in the BWH as Director of Andean Affairs and Deputy Asst. Secretary. From 2003 to 2005, Shannon returned to the National Security Council as senior aide to Condoleezza Rice. He began his term as assistant secretary of the Bureau of Western Hemisphere Affairs October 7, 2005.