"Dr. Kissinger will bring broad experience, clear thinking and careful judgment to this important task," Bush said at a signing ceremony in the Roosevelt Room of the White House. "Mr. secretary, thank you for returning to the service of your nation."

The commission has a broad mandate, building on the limited joint inquiry conducted by the House and Senate intelligence committees. The independent panel will have 18 months to examine issues such as aviation security and border problems, along with intelligence.

Bush called on members to report back more quickly than 18 months, saying the nation needed to know quickly how it can avoid terror attacks in the future. "The sooner we have the commission's conclusions, the sooner we can act on them," Bush said.

"This should carefully examine all evidence and follow all facts, wherever they lead," the president said.

However, Bush did not set as a primary goal for the commission to uncover mistakes or lapses of the government that could have prevented the Sept. 11 attacks. Instead, he said it should try to help the administration learn the tactics and motives of the enemy.

"This commission will help me and future presidents to understand ... the nature of the threats we face," he said.