Sixty percent of Americans say the war in Afghanistan has not been not worth fighting and just 30 percent believe the Afghan public supports the U.S. mission there - marking the sour state of attitudes on the war even before the shooting rampage allegedly by a U.S. soldier this weekend.

Indeed a majority in a new ABC News/Washington Post poll, 54 percent, say the United States should withdraw its forces from Afghanistan without completing its current effort to train Afghan forces to become self-sufficient.

The survey was completed Saturday. Early Sunday a U.S. service member allegedly left his base in Kandahar and shot and killed more than a dozen civilians in two nearby villages, an incident certain to raise tensions already inflamed by the U.S. military's inadvertent burning of Muslim holy books at Bagram Air Base last month. That incident sparked violent protests, including a series of incidents in which Afghan soldiers have turned their guns on U.S. forces.

Against that backdrop, the number of Americans who say the war has not been worth fighting, at 60 percent, is up by 6 points from its level last June to just 4 points from its peak, 64 percent, a year ago. Intensity of sentiment is deeply negative: Forty-four percent feel "strongly" that the war has not been worth fighting. Just 17 percent, by contrast, support it strongly.

Criticism of the war had been assuaged to some extent last year by the drawdown of U.S. forces, a step backed by 78 percent of Americans in an ABC/Post poll last month. Taking another tack, this poll, produced for ABC by Langer Research Associates, asked if the United States should keep its forces in Afghanistan until it has trained the Afghan Army to be self-sufficient, or withdraw even without accomplishing that task. Given those competing interests, 43 percent favor completing the training effort; 54 percent, as noted, opt for withdrawal regardless.

While the war lacks majority support on the basis of a cost-benefit evaluation for the United States, support is further eroded by the fact that 55 percent of Americans think most Afghans themselves do not support U.S. efforts in their country, and an additional 15 percent are unsure. Just three in 10 think the U.S. mission enjoys majority support.

Partisanship informs views on the war. Democrats and political independents see it as not worth fighting by broad 40- and 31-point margins, respectively, while Republicans divide evenly on the question. Similarly, liberals and moderates are critical of the war by 49- and 27-point margins; conservatives share this view much more narrowly, by 9 points. And while nearly six in 10 Republicans favor staying until Afghan forces are trained, that drops to 37 percent among others.

A renewal of critical views could have political ramifications for President Obama's re-election effort. Discontent with the war in Iraq, at similar levels as views on Afghanistan today, badly damaged George W. Bush's presidency, marking the risk for Obama, especially in an election year.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone March 7-10, 2012, among a random national sample of 1,003 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 4.0 points for the full sample. The survey was produced for ABC News by Langer Research Associates of New York, N.Y., with sampling, data collection and tabulation by Abt-SRBI of New York, N.Y.