Democratic presidential candidate Wesley Clark (search) on Tuesday criticized the timing of an investigation of former Treasury Secretary Paul O'Neill (search) and suggested President Bush was more concerned with "political security" than national security.

Campaigning in New Hampshire two weeks before its primary election, Clark called for a full congressional investigation into why the United States went to war in Iraq (search).

"We don't know what the motivation was. We just don't know. We've spent $180 billion on it, we've lost 480 Americans, we've got 2,500 with life-changing injuries," the retired general told reporters.

Clark contended that Bush was obsessed with Iraqi leader Saddam Hussein, and with establishing a national missile defense, in the months leading up to the Sept. 11, 2001, terror attacks -- and did not do enough to protect the nation against such an attack.

In a book released Tuesday, O'Neill criticized Bush's leadership style and suggested he planned to go after Saddam even before the attacks.

The Treasury Department announced on Monday that it was launching an inspector general's investigation into how an agency document stamped "secret" wound up being used in O'Neill's interview Sunday night on the CBS program "60 Minutes."

O'Neill, who was fired a year ago in a shake-up of the Bush economic team, has denied that classified documents were used in a book about his two years in the administration.

Clark contrasted the speed of the O'Neill investigation with the slow pace of an inquiry into who last summer divulged the name of a CIA official whose husband had criticized the president's Iraq policy.

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"They didn't wait 24 hours in initiating an investigation on Paul O'Neill," Clark said. "They're not concerned about national security. But they're really concerned about political security. I think they've got their priorities upside down."

Democratic candidate Howard Dean echoed the criticism: "Paul O'Neill is not a threat to our national security," he said in a statement. "But the disclosure of the identity of an undercover CIA operative undermines a key tenet of national security and is a violation of law."

Clark has bypassed Monday's Iowa caucuses in hopes of scoring well in the New Hampshire first-in-the-nation primary Jan. 27.

The retired general told participants in a round-table discussion in Manchester that his proposal to repeal Bush's tax cuts and ending all taxes on families earning under $50,000 would lift more than 1 million Americans out of poverty.

During the course of the campaign, Clark has tried to hitch his star to former President Clinton, and in a conference call with reporters Tuesday, Clark aides said the last Democratic president has reviewed Clark's position papers, analyzed polling data and even referred a major donor to Clark.

The other campaigns have said their candidates have spoken to Clinton as well, seeking advice and guidance. Aides have said the former president would not endorse in the primary race.

Several former Clinton administration officials now working for Clark plan to campaign for him in New Hampshire this weekend.