Democratic presidential candidates pounced on rival Hillary Clinton for her positions on Iraq and Iran in a debate on Wednesday as they sought to undercut her status as the campaign front-runner. Former North Carolina Sen. John Edwards, a distant third place in most national polls and needing a breakthrough performance, led the attack against Clinton on the campus at Dartmouth College. With the Democratic left-wing demanding a hasty U.S. timetable out of Iraq, Edwards criticized the New York senator for not ruling out that U.S. troops might engage in some combat missions in Iraq if she were to win the 2008 election.

"To me that's a continuation of the war," Edwards said. "Combat missions mean that the war is continuing. I believe the war needs to be brought to an end."

Edwards' broadside put Clinton on the defensive at a time when she is enjoying a comfortable lead in opinion polls and trying to appear above the fray. But there was no sign that the debate would prompt a major shake-up in the Democratic field.

"There may be a continuing counter-terrorism mission," she said, while adding that "the vast majority" of American troops would be out of Iraq by the end of her prospective first term in 2013.

The cross-fire on the campus of Dartmouth College came at the first debate of the critical autumn season leading up to the early voting contests in January ahead of the November 2008 election to replace President George W. Bush.

Iraq was a dominant theme of the debate as Democrats seek a way to force Bush to change his war strategy, which may leave as many as 100,000 troops there by the time the next president is inaugurated in January 2009.