Robert Gates, the former CIA director, maneuvered through five hours of nonconfrontational Senate questioning, winning approval to replace Donald H. Rumsfeld as secretary of defense. He raised some eyebrows by stating bluntly that the United States is not winning in Iraq, in the process contradicting President George W. Bush, who said at an Oct. 25 news conference, "Absolutely, we're winning." Gates later stressed that the United States also is not losing, and the setbacks have been more political than military. After the Senate Armed Services Committee voted 24-0 on Tuesday to recommend Gates be confirmed, Senate Majority Leader Bill Frist announced that floor debate on the nomination would begin Wednesday. "I am confident that Dr. Gates fully understands the need for victory in Iraq," Sen. John Cornyn said after the committee's vote. "Failure in Iraq would lead to increased terrorist activity by al-Qaida and regional instability as Iran tries to extend its sphere of influence."