President Obama arrives at the White House on Aug. 9, 2011, after making an unannounced trip to Dover Air Force Base, in Dover, Del., to pay tribute to the 30 U.S. troops killed over the weekend in Afghanistan. (Associated Press)

Photo by: Pablo Martinez Monsivais

President Obama arrives at the White House on Aug. 9, 2011, after making an unannounced trip to Dover Air Force Base, in Dover, Del., to pay tribute to the 30 U.S. troops killed over the weekend in Afghanistan. (Associated Press)