Panetta becomes Pentagon chief

A day after stepping down as CIA director, Leon Panetta was sworn in Friday as secretary of defense.

Panetta succeeds Robert Gates, who was a Republican holdover from the George W. Bush administration, and is the first Democrat to run the Pentagon since William J. Perry finished his tenure in 1997.

In his written message, issued moments after his swearing in, Panetta said that in his 2 1/2 years as CIA chief he appreciated the military's capabilities, and he promised that as Pentagon chief he would do all he could to maintain that strength.

"Our nation is at war," he wrote. "We must prevail against our enemies. We will persist in our efforts to disrupt, dismantle and ultimately defeat al-Qaida."