A conversation with... Robert Gates served as the 22nd secretary of defence, from 2006 to 2011, and is the only secretary of defence in US history to be asked to remain in that office by a newly elected President. President Barack Obama is the eighth president Gates has served. He previously served under President George W Bush. On Gates’ last day in office, President Barack Obama awarded him the Presidential Medal of Freedom, America’s highest civilian honour. Gates joined the Central Intelligence Agency in 1966 and spent nearly 27 years as an intelligence professional. During that period, he spent nine years at the National Security Council, the White House, serving four presidents of both political parties.