April 9 (Bloomberg) -- Voters will choose a new U.S. president in November with as many as 140,000 American troops still in Iraq and no clear plan for extricating them from the unpopular conflict.

That is the upshot of Army General David Petraeus's testimony to the Senate yesterday and to the House today, in which the U.S. commander in Iraq advocated delaying further force reductions until September at the earliest.

Petraeus's recommendation, which President George W. Bush has already signaled he will accept, increases the importance of the Iraq issue for all the presidential contenders.

For the presumptive Republican nominee, Senator John McCain of Arizona, who has tethered his political fate to the war, the freeze could hurt or help him, said Julian Zelizer, a history and public affairs professor at Princeton University in New Jersey.

The U.S. military role in Iraq ``will constantly remind voters about a Republican problem that is unpopular, controversial and seen as a policy failure,'' Zelizer said. At the same time, Democrats shouldn't assume the war issue will break their way.

``Americans often support hawks or military figures to get the nation out of messy wars,'' he said, citing Presidents Dwight Eisenhower, who ended the Korean War in 1953, and Richard Nixon, who brought most U.S. forces home from Vietnam 20 years later.

Obama, Clinton

McCain and the two Democratic presidential candidates -- Senators Barack Obama of Illinois and Hillary Clinton of New York -- addressed Iraq yesterday as Petraeus and U.S. Ambassador Ryan Crocker appeared before two Senate committees.

Clinton, 60, said it was time to begin an ``orderly process'' of withdrawal. Obama said setting a timetable for a pullout would force Iraqi leaders to resolve sectarian disputes.

The Democratic rivals are responding to weak public support for the Iraq war. Sixty percent of all Americans favor setting a timetable for removing U.S. forces, while 35 percent support keeping a significant number of troops there until the situation improves, according to a USA Today/Gallup poll taken Feb. 21 through Feb. 24.

McCain, 71, reiterated his view that the U.S. troop buildup ordered by Bush last year has been a success and that a premature American withdrawal would be ``reckless and irresponsible.''

No `Abyss'

``We're no longer staring into the abyss of defeat, and we can now look ahead to the genuine prospect of success,'' McCain said.

At the same time, McCain sought to refute Democratic criticisms that he supported an unlimited U.S. commitment and was overly optimistic about the course of the conflict.

McCain said his goal was ``an Iraq that no longer needs American troops.'' And he elicited testimony from Petraeus that was critical of the performance of Iraqi Prime Minister Nuri al- Maliki and Iraqi security forces in fighting against Shiite militias in Basra.

Clinton, like McCain a member of the Senate Armed Services Committee, also used her moment in the spotlight to counter critics of her position on Iraq -- in this case, McCain and his assertion that those supporting withdrawal were irresponsible.

``It might well be irresponsible to continue the policy that has not produced the results that have been promised time and time again at such tremendous cost,'' Clinton said.

The administration and its supporters ``often talk about the cost of leaving Iraq, yet ignore the greater cost of continuing the same failed policy,'' she said.

`Strategic Blunder'

Obama, 46, a member of the Foreign Relations Committee, said Bush's decision to invade Iraq was a ``massive strategic blunder.''

``Our military is overstretched and the Pentagon has acknowledged it,'' he said. ``When you have finite resources, you've got to define your goals tightly and modestly.''

The core of Petraeus's testimony dealt with what to do after the last of five U.S. combat brigades sent to Iraq last year in Bush's ``surge'' buildup come home at the end of July.

Petraeus, 55, said the progress made in Iraq was too ``fragile and reversible'' to permit further troop reductions right away. He advocated a 45-day period of ``consolidation and evaluation'' after which new drawdowns could be considered, while refusing to commit to any timetable for making such reductions.

Issue for Voters

Because an occupation force of about 140,000 troops may be present in Iraq well beyond September, and conflicts and instability there are likely to persist, ``it's very possible that the war may become the most important issue for voters in November,'' said Stephen Schneck, a political scientist at Catholic University in Washington.

McCain appears to be ``betting his candidacy on an improving military and political situation,'' Schneck said. ``Neither Crocker nor Petraeus were willing to go so far in their speculations.''

Petraeus emphasized that ``we haven't turned any corners, we haven't seen any lights at the end of the tunnel, the Champagne bottle has been pushed to the back of the refrigerator.''

Schneck said yesterday's comments indicate that McCain ``obviously believes his candidacy's strengths lie with issues of war and terror,'' while both Obama and Clinton believe they can capitalize on the war's unpopularity.

In that sense, he said, yesterday provided ``a true taste of the fall political season.''

To contact the reporter on this story: Ken Fireman in Washington at kfireman1@bloomberg.net; Kristin Jensen in Washington at kjensen@bloomberg.net

Last Updated: April 9, 2008 10:27 EDT