Americans may question this war for many reasons, but their doubts often find voice in the count of U.S. war deaths. An overwhelming majority - 84 percent - worry that the war is causing too many casualties, according to a September poll by the nonpartisan research group Public Agenda.
The country largely kept the faith during World War II, even as about 400,000 U.S. forces died - 20,000 just in the monthlong Battle of the Bulge. Before turning against the wars in Korea and Vietnam, Americans tolerated thousands more deaths than in Iraq.
Has something changed? Do Americans somehow place higher value on the lives of their Soldiers now? Do they expect success at lower cost? Or do most simply dismiss this particular war as the wrong one - hard to understand and harder to win - and so not worth the losses?
The Associated Press recently posed these questions to scholars, veterans, activists, and other Americans. Their comments suggest that the public does express more pain over the deaths of this war.
A death toll of 3,000 simply sounds higher to Americans in this war than it did in other prolonged conflicts of the past century, for a number of reasons, the interviews suggest.
"As fewer Americans die in war, their loss is more keenly felt, not necessarily at a personal level, but at a collective and public level," says historian Michael Allen at North Carolina State University.
Jeffrey Greenwood, 17, of Plymouth, Mass., though unsure of the exact number of Iraq war deaths, says, "I know it's enough to make people angry."
John Mueller, a political scientist at Ohio State University, calls this casualty sensitivity "the Iraq syndrome." He described it in an influential journal article last year: "Casualty for casualty, support has declined far more quickly than it did during either the Korean War or the Vietnam War."
In the weeks after the U.S. invasion of Iraq in March 2003, public backing was powerful. But opinion began to shift quickly once the Iraqi army was beaten, its leader was forced into hiding, and chemical, biological or nuclear weapons were not found.
- By late 2003, public support for the occupation began to seesaw around 50 percent, according to Richard Eichenberg, a political scientist at Tufts University.
- In September 2005, 55 percent of Americans favored stronger efforts to withdraw because of the losses, a Gallup poll found.
- Last October, 54 percent of registered voters believed the war wasn't worth the U.S. casualties or cost, a Hart-McInturff poll found. In November, voters reversed the congressional balance of power in an election viewed as a referendum on Iraq.
Polling analysts believe Americans are more sensitive to casualties than in the past because they neither see vital interests at stake nor feel the "halo effect" from a clear prospect of success.
At the same time, scholars suggest that America's instant technologies and its global power have conditioned its population to expect quick, painless results in almost any war.
"In a world of smart bombs and so on, you just expect the military to be able to insulate the military from getting killed - and to a large extent they have," says Christopher Gelpi, a casualty researcher at Duke University.
Precision air power helped the U.S. military succeed in the former Yugoslavia and the first war with Iraq, and scholars say that lowered the expectation of casualties in future wars. Improvements in body armor may have contributed to the same expectation.
Speed-of-light consumer conveniences, like cellular phones and digital cameras, also reinforce expectations of fast results that spill over into war, some scholars say. In what's called "the CNN effect," the unblinking eye of video news and unending chatter of the Internet quicken and maybe intensify the public's reaction to the carnage of battle.
"The American people have never been known for their patience, and I suppose with these 24-7 news cycles and access to the Internet, everything seems to have accelerated," says Richard Melanson, who teaches a class on public opinion and foreign policy at the U.S. military's National War College, in Washington, D.C.
America's young no longer feel personally threatened, either. The military draft is history. These days, mostly working-class teenagers volunteer to do the fighting.