gates was nominated by republican president george w. bush as secretary of defense after the 2006 election, replacing donald rumsfeld. he was confirmed with bipartisan support. in a 2007 profile written by former national security advisor zbigniew brzezinski, "time" named gates one of the year's most influential people. in 2008, gates was named one of america's best leaders by "u.s. news & world report". he continued to serve as secretary of defense in president barack obama's administration. he retired in 2011. "he'll be remembered for making us aware of the danger of over-reliance on military intervention as an instrument of american foreign policy," said former senator david l. boren. gates was presented the presidential medal of freedom, the nation's highest civilian award, by president obama during his retirement ceremony.