SECURITY -- Public assessments of the war have turned more negative even though more than half of Americans, 53 percent, say it has contributed to the long-term security of the United States, unchanged from last summer. Far fewer, 22 percent, say the war's contributed a "great deal" toward U.S. security.
It makes a difference: Among people who see a great deal of added security as a result of the war, 63 percent say it's been worth fighting. But among those who say it's contributed, but only somewhat, support for the war falls to 49 percent. And among the four in 10 Americans who say the war has not enhanced U.S. security, or who are unsure, support plummets to 11 percent.
The sharpest decline in views that the war has been worth fighting -- down 14 points since July -- has come among people who also say it's provided a "great deal" of additional security. It may be their sense that no more additional security benefits for the United States can be derived; or that, regardless, the costs no longer justify the gains.
In any case, these results mark the cost/benefit analysis the public employs in evaluating war: Whether the gains, either in security or other measures, are worth the costs, including in terms of lives and dollars. As was the case in Iraq, with casualties up and dollar costs high, the public increasingly is questioning the value proposition of the war in Afghanistan.
GROUP DIFFERENCES -- Republicans have been and remain substantially more supportive of the war, a conundrum for Obama in that the group that most favors the war least likes his handling of it. In any case, views that it's been worth fighting are at new lows across the board.
Half of Republicans now say it's not been worth it, down a dramatic 35 points from the high in 2007. Support drops sharply from there, to 31 percent among independents and a quarter of Democrats, down 27 and 16 points, respectively, from their highs. Views of the war as "worth fighting" are down by 10 or 11 points in all three groups since summer.
Republicans also are more apt than Democrats to think the war has contributed to long-term U.S. security, by a 20-point margin, 70 percent to 50 percent; more likely to support the troop surge, 62 vs. 48 percent; and more apt to say the withdrawal of U.S. forces start later than next summer. But even among Republicans, just 24 percent support a slower start to the withdrawal process.
METHODOLOGY -- This ABC News/Washington Post poll was conducted by telephone Dec. 9-12, 2010, among a random national sample of 1,001 adults, including landline and cell-phone-only respondents. Results for the full sample have a 3.5-point error margin. Click here for a detailed description of sampling error. This survey was produced for ABC News by Langer Research Associates of New York, N.Y, with sampling, data collection and tabulation by TNS of Horsham, Pa.
ABC News polls can be found at ABCNEWS.com at http://abcnews.com/pollingunit