A major overhaul of the national-security team is under way. Secretary of Defense Robert Gates, a holdover from the Bush administration who has stayed on the job during the first two years of Barack Obama's presidency, will step down June 30, sources tell the Associated Press. Obama is expected to tap Leon Panetta, the current director of the CIA, to succeed Gates at the Pentagon. Obama's choice to succeed Panetta as top spook: Gen. David Petraeus, according to sources. Petraeus is the commander of U.S. forces in Afghanistan.