By KEN GUGGENHEIM
Associated Press Writer

WASHINGTON (AP) - President Bush named seven people Friday to sit on an independent study commission to look into intelligence failures on Iraqi weapons, choosing former Democratic Sen. Charles S. Robb and retired judge Laurence Silberman, a Republican, to head the panel.

"We must stay ahead of constantly changing intelligence challenges," Bush said. "The stakes for our country cannot be higher."

Robb was a former U.S. senator and governor of Virginia and son-in-law of the late President Johnson. He is married to Lynda Baines Johnson and has been practicing law since leaving the Senate. Silberman is a conservative who served as deputy attorney general in the Nixon and Ford administrations. He was named to the appeals court by President Reagan in 1985.

Bush also picked Sen. John McCain, R-Ariz., to be a member of the commission.

Bush had come under increasing pressure from Democrats in recent days in the wake of the admission by chief weapons inspector David Kay that he could not substantiate that Saddam Hussein had the kind of weapons arsenal the administration maintained was in existence, and which it used to justify the invasion of Iraq.

Bush also named Lloyd Cutler, former White House counsel to Presidents Carter and Clinton; former federal judge Patricia M. Wald; Yale University president Richard C. Levin, and Adm. William O. Studeman, former deputy director of the CIA.

Wald, a respected former chief judge for the U.S. Circuit Court of Appeals for the District of Columbia, served as a judge on the International Criminal Tribunal for the former Yugoslavia.

In a visit to the United Nations, where he relied on Tenet's intelligence in a futile attempt for Security Council backing for the war, Powell said Friday: "I don't think any apologies are necessary."

"It represented the best judgment we had" and "there is no evidence to suggest we were wrong,' he said. And yet, Powell acknowledged "we could not be sure of the nature of the stockpile."

U.N. Secretary General Kofi Annan said, "It is ironic that Secretary of State Colin Powell is in the building. There has been some damage. Damage that probably will take some time to heal. People are going to be very suspicious when we try to use intelligence to justify certain actions."

But, Annan also said that inelligence is necessary for government work and said that "we need to be careful not to throw everything out of the window."

Bush had initially opposed a commission, but agreed to do so as calls grew from Republican lawmakers as well as Democrats. But the White House said the commission would look beyond problems in Iraq and examine the handling of intelligence on terrorists and U.S. adversaries.

Democrats said any commission appointed solely by Bush could not be considered independent and objective. They have called for an examination not only of the work of intelligence agencies, but whether the White House pressured analysts and manipulated data to boost the case for war.

Kay, the former CIA adviser for the Iraqi weapons search, has said he does not believe analysts were pressured. But he said Thursday that the commission should look into whether political leaders manipulated intelligence data.

"I think that is an important question that needs to be understood," he said Thursday at the Carnegie Endowment for International Peace.

CIA Director George Tenet offered a forceful defense of prewar intelligence in a speech at Georgetown University Thursday. He said the intelligence was mostly on target and that the analyses were reasonable given the information available to the United States and other nations.

He made clear that analysts differed on important aspects of Saddam Hussein's chemical, biological and nuclear programs. Tenet said analysts had never claimed Iraq posed an imminent threat, but provided an objective picture of Saddam's efforts to build and conceal weapons programs. He also said that no one told analysts "what to say or how to say it."

On Friday morning, Bush met with Charles Duelfer, who is taking over the weapons search in Iraq, and told him that he "wants him to find the truth ... it is important that we know all the facts," McClellan said.