Edwards: Bush Waging War 'Without Authorization'

Former Sen. John Edwards, D-N.C., said Wednesday that President Bush is waging war in Iraq "without authorization." A GOP spokesman called Edwards' claim "preposterous," but a leading national security expert disagreed with that assessment.

"We need to make clear, the Congress needs to make clear," said Edwards, "that President Bush has been conducting this war at this stage without authorization, because the 2002 authorization did not give George Bush authority to use U.S. combat troops to police a civil war, which is exactly what's happening right now."

Edwards, who was the Democratic Party's 2004 vice presidential nominee, made his comments on a conference call with reporters in which he urged members of Congress to cap U.S. troop levels in Iraq at 100,000.

Dan Ronayne, a Republican National Committee spokesman sharply rebuked Edwards, pointing to the former senator's 2002 vote that authorized the president to use the U.S. Armed Forces "as he determines to be necessary and appropriate in order to defend the national security of the United States against the continuing threat posed by Iraq."

"John Edwards voted for the war in Iraq," said Ronayne. "His comment is preposterous."

Invoking an interview that Sen. Joe Biden, D-Del., a Democratic presidential candidate, recently gave to the New York Observer, Ronayne said Biden "might have been right when he said Edwards doesn't know what he's talking about when it comes to Iraq."

Stephen Dycus, a Vermont Law School professor and the author of the leading casebook on national security law, told ABC News that the Iraq War resolution, which Edwards supported, is "very broadly drawn."

"It's a little bit like someone described the Gulf of Tonkin Resolution authorizing the war in Vietnam: 'It's like grandma's nightshirt. It covers everything,'" said Dycus.

Despite the broad wording of the Iraq War resolution, Dycus believes it is reasonable for Edwards to argue that the president's authority is constrained by the original purpose for which the power was granted.

"A good argument," said Dycus, "can be made that the president needs to come back to Congress because the stated purpose of the original resolution either didn't exist, or has been accomplished."

ABC News' Matthew Zavala contributed to this report.