A poll of U.S. troops in Iraq indicates that many of them believe the force should be withdrawn within a year, and some say sooner. A Defense Department spokesman says there are other indications that many of the troops understand the importance of their mission and want to see it through to a successful conclusion.

Senior U.S. officials, including Defense Secretary Donald Rumsfeld, are fond of citing support among the troops as evidence that their policy in Iraq is a good one. But the survey by the well-known Zogby International polling company says 72 percent of the U.S. troops in Iraq believe all U.S. forces should be withdrawn within 12 months. Among them, 29 percent called for an immediate withdrawal and 22 percent said the force should leave within six months. According to the survey, only 23 percent say U.S. troops should stay in Iraq "as long as they are needed," which is President Bush's policy.

"One in four agree that they need to stay there until the mission is done. But the fact of the matter is that the overwhelming majority, meaning the rest, three out of four, say that they don't think the mission can be accomplished," said polling agency head John Zogby.

And the rare independent poll of deployed U.S. troops indicates that that mission is not entirely clear to the troops, even though most of those surveyed are on their second or third tour in Iraq.

Fifty-eight percent say they understand the mission, but their understanding does not reflect what senior officials say. Officials say the mission is to nurture democracy, train Iraqi forces and help the Iraqi government gain the capability to take full control of the country in a reasonably peaceful environment. The survey says the troops believe the mission is to retaliate for what they say was Saddam Hussein's role in the September 11 attacks, and to prevent him from allowing Iraq to become a safe haven for the al-Qaida terrorist network.

Defense Department spokesman Bryan Whitman says the survey is not a definitive account of the views of U.S. troops in Iraq. He says there are other reliable indicators of the soldiers' views, including what they tell their commanders, who report that morale and commitment to the mission are high. And Whitman cites what he sees as a strong indicator of that.

"If you look at the retention statistics, some of our highest retention rates units that are deployed and are on the front lines in the global war on terror - on the front lines in Iraq, on the front lines in Afghanistan - people that perhaps are able to observe first-hand the importance of the work that they're doing and want to be a part of the history of this country, and are proud of their service and want to continue their service," he said.

The Pentagon spokesman says no one in the Defense Department is alarmed by this survey, which he called only "one piece of data" in the "totality" of the Iraq situation.

And he says it will not affect the next review of U.S. troop strength in Iraq, which is expected in the next few months. He says any decision on possible future reductions will be based on an assessment by senior commanders of the readiness of Iraqi forces, the strength of the insurgency, the stability and capability of the new Iraqi government and related factors.

The Center for Peace and Global Studies at small LeMoyne College in New York State was also involved in the survey. The Center's director, Professor Barron Boyd, notes that sentiment in favor of a rapid withdrawal was particularly strong among U.S. reserve and National Guard troops in Iraq. They are part-time soldiers who have been called to more than a year of dangerous duty.

"I find it hard to imagine that there's not something of a correlation between the situation that the Guard and the reserves find themselves in and their desire to get home quickly. Now, it's not the only factor, but it's not an inconsiderable part of the policy analysis question as well, in my opinion," he said.

Still, the survey says 58 percent of U.S. marines in Iraq believe U.S. troops should be withdrawn within a year. Marines are traditionally among the most committed of all U.S. forces.

The survey also indicates that 80 percent of U.S. troops say the thousands of attacks against them by Iraqi insurgents have not given them a negative view of the Iraqi people.

The Zogby organization says the interviews of 944 U.S. troops were conducted at four undisclosed locations in Iraq during January and February. The group says the poll has a margin of error of 3.3 percent. Pentagon Spokesman Bryan Whitman says as far as he knows, the pollsters were not given permission to enter military bases in Iraq, but he says it is not against the rules for troops to talk to pollsters. The Zogby group says the pollsters had verbal permission from commanding officers at the four facilities.

The company also acknowledges that the survey was funded by a wealthy anti-war activist, but it says he had nothing to do with the way the questions were formulated or how the answers were analyzed.