Washington ? President Bush appointed former Secretary of State Henry Kissinger to lead an investigation into why the government failed to foil the Sept. 11 attacks, telling the veteran diplomat to “follow all the facts wherever they lead.”

Signing a bill he once opposed, Bush told survivors and victims’ family members on Wednesday, “We must uncover every detail and learn every lesson” from the terrorist strikes. The bill creates a 10-member independent panel for an 18-month inquiry into the attacks on Washington and New York that killed more than 3,000.

Debate about the commission has been marked by differences between the White House, Democrats and victims’ relatives over how far the probe should go and whether Bush himself should testify.

Kissinger’s appointment gives the commission instant respectability, and puts a White House ally in charge of an inquiry that has the potential to embarrass Bush.

Kissinger, 79, echoed the president in pledging to “go where the facts lead us.” He said he would accept no restrictions.

Later, Democratic congressional leaders named former Senate Majority Leader George Mitchell to be vice chairman of the panel. After leaving the Senate in 1995, Mitchell led the negotiations that produced the landmark Good Friday peace pact of 1998 for Northern Ireland.

The commission will build upon the work of congressional investigators who reported this year that clues to the hijackers’ plot were ignored or misunderstood.

Lawmakers have criticized the CIA for not tracking two al-Qaida operatives it learned of in early 2000. Those operatives were two of the five hijackers on the plane that crashed into the Pentagon.

Former Secretary of State Henry Kissinger will lead a new independent commission to investigate the Sept. 11 attacks. Kissinger's appointment was announced Wednesday by President Bush.

Congressional investigators also noted poor communication between the FBI and CIA, and questioned the State Department on visa programs that allowed all 19 hijackers to enter the country unchallenged.

“This commission will help me and future presidents to understand the methods of America’s enemies and the nature of the threats we face,” Bush said at a ceremony across the hall from the Oval Office.

The commission has a broad mandate to examine issues such as aviation security and border problems, along with intelligence.