Democratic presidential candidates took part in a "virtual" forum on the Iraq war Tuesday, with Barack Obama chiding GOP rival John McCain for using a heavily guarded visit to a Baghdad market as evidence that security is improving.

"The idea that the situation in Iraq is improving because it takes a security detail of 100 soldiers, three Black Hawk helicopters and a couple of Apache gunships to walk through a market in the middle of Baghdad is simply not credible and not reflective of the facts on the ground," Obama said in a taped interview broadcast as part of the forum sponsored by MoveOn.org.

While not mentioning McCain by name, Obama criticized comments made by the Arizona senator last week after touring Baghdad's Bab al-Shariq market. He and other members of a congressional delegation traveled in armored military vehicles and wore body armor during the hourlong excursion.

McCain's campaign declined to comment on the Illinois senator's statement. But on Monday, McCain said he was told by many Iraqis in the market that they felt as though things were getting better.

Seven Democrats participated in the online forum, fielding questions about the Iraq war submitted by MoveOn members. Afterward, members could vote on which candidates' positions they favor, with the results to be announced Thursday.

The candidates agreed that the problems facing Iraq require a political engagement rather than military force, and each called for a specific timetable for American troops to be removed from the country. All said they believed Iraq's neighbors, including Syria and Iran, must be engaged to help stabilize the region.

Front-runner Hillary Rodham Clinton, a target of criticism in the online world for her refusal to recant her 2002 vote authorizing military action in Iraq, thanked MoveOn for being "such lively participants" in the political debate.

"Some of your members may be a little surprised to hear me say this, I am grateful for your work," she said.

The New York senator touted her online petition calling on President Bush not to veto legislation tying funding for the war to a timeline for troop withdrawal. But she and Obama both sidestepped questions on whether they would vote for a funding bill that stripped out a timetable for redeployment.

"I don't think we should tell President Bush what we will do if he vetoes this legislation. We need to keep the pressure on him not to veto it," Clinton said.

For his part, former North Carolina Sen. John Edwards insisted Congress must use its funding authority to de-escalate the conflict. Edwards voted in 2002 to authorize the war but has since apologized.

"If Bush vetoes funding for the troops, he's the only one standing in the way of the resources they need. Nobody else," Edwards said. "Congress must stand firm. They must not write George Bush another blank check without a timeline for withdrawal — period."

Delaware Sen. Joe Biden discussed his proposal to divide the country along ethnic lines, with a central government providing border security and dividing up oil revenues.

"Oil should be what binds the country, not what splits it apart," Biden said.

Dodd spoke in favor of developing and energy policy that would minimize the need for access to Iraq's oil.

"Energy independence within 10 years is something I'm strongly advocating. I believe the American people would be more than delighted to participate in an idea that will allow us to achieve that kind of independence," he said.

New Mexico Gov. Bill Richardson, who served in the House for 15 years, called on Congress to revoke its original authorization for the war.

"I believe that's a clearer, cleaner course and the thrust of the American people would be clear," Richardson said. "I admire what congress is doing, I think they need to be stronger.

Ohio Rep. Dennis Kucinich championed a plan to put the United Nations peacekeeping troops in charge of Iraq's security, with at least 50 percent coming from Muslim nations. He also said the U.S. must commit to a massive reparations effort in Iraq.

"It's a test of our morality," he said.

With 3.8 million members, MoveOn has become an influential force in the anti-war "netroots" community. While it has raised substantial money for candidates over the years and unleashed its online presence to influence elections, it has had a mixed record of success.

MoveOn helped elect several Democrats in 2006 to win control over both houses of Congress. The organization also actively promoted an anti-war candidate, Ned Lamont, who lost badly Sen. Joe Lieberman in Connecticut after defeating him in the Democratic primary.