The 2008 TIME 100

Robert Gates was President George W. Bush's surprising choice as Secretary of Defense. When he accepted that onerous appointment — in the midst of a painful war and two years before the end of the President's term in office — he simply stated that he felt it was his duty to serve.

Having known him for some 30 years, I know this statement was sincere. Gates, above all, is a patriot. But he happens to be also a very intelligent patriot, and that is truly reassuring. During his confirmation hearings before the Senate, Gates, 64, acknowledged the important role of Congress in any decision to initiate a new war. That earned him widespread bipartisan respect — and a wartime Secretary of Defense needs such support, particularly when the war is so unpopular.

Gates' professional career has focused predominantly on national security issues. He served on the National Security Council (NSC) staff under Brent Scowcroft during the Ford presidency. He then became my special assistant when I was in charge of the NSC under President Jimmy Carter. He was the first person I would see every morning and usually the last one in the evening. I came to value highly his grasp of foreign affairs and his political judgment.

His meteoric rise continued at the CIA, where he eventually became director under President George H.W. Bush. Cool, calm and collected, this is a man who would never be rattled by a sudden 3 a.m. phone call.

Brzezinski was National Security Adviser to U.S. President Jimmy Carter