Pakistan, while Allen became deputy commander of U.S. Central Command in July 2008. Gates is the only Cabinet member from the previous administration to stay on when Obama came into office. President George W. Bush nominated Gates as the nation's 22nd secretary of defense in December 2006 to replace Donald Rumsfeld, one of the architects of the Iraq War who was facing widespread criticism. Gates did not expect to stay on after Bush's presidency ended. When asked if he would continue under another administration, Gates said in 2008, I learned a long time ago never to say never, so my answer is: The circumstances under which I would do that are inconceivable to me. But those circumstances arose. In December 2008, then-President-elect Obama expressed a desire for continuity at the Pentagon, given the ongoing conflicts abroad in Iraq and Afghanistan. I spent a long time hoping the question would never be popped, Gates admitted the day after Obama announced his nomination. But, he said, Obama impressed him. It is unclear who may replace Mueller at the FBI. Attorney General Eric Holder on Tuesday did not rule out Mueller staying on short-term when his 10-year term expires in September if a successor has not yet been confirmed. Mueller will leave hard shoes to fill, Holder said. Holder said he has been discussing potential nominees with White House officials, including Vice