Broad opposition in the new poll contrasts with a December Post-ABC poll that found most Americans saying they would be supportive of U.S. action if Syria used chemical weapons. At that time, 63 percent supported U.S. military involvement when it was a hypothetical situation, while 30 percent were opposed.
Such possible support for action has yet to materialize in the weeks after an August 21 gassing that reportedly killed 1,429 people outside of Damascus. The survey was conducted Wednesday through Sunday, as the Obama administration made its public case for military strikes and presented intelligence claiming "high certainty" that Syria's government is the culprit in attacks.
Americans express more support for action if Britain and France were to join the cause, a prospect that became far less likely after the British parliament shot down a proposal for military action in Syria. In the United States, support for missile strikes in Syria rises by 10 percentage points, to 46 percent, if Britain and France participate, including a 14 point jump among independents. Still, 51 percent remain opposed even if such a coalition materialized.
The public expresses even wider opposition to arming Syrian rebels, which President Obama authorized in June. Fully seven in 10 oppose arming rebels, including large majorities of Democrats, Republicans and independents.
The poll finds somewhat lower support for military action than an NBC News poll conducted Wednesday and Thursday of last week. In that survey, 42 percent supported military action, rising to 50 percent for limited strikes targeting Syria's chemical weapons facilities. Here is a link to the wording and results in that survey.
The Post-ABC poll was conducted by telephone Aug. 28-Sept. 1, 2013, among a random national sample of 1,012 adults, including users of both conventional and cellular phones. The margin of sampling error for overall results is plus or minus 3.5 percentage points.
Jon Cohen and Peyton M. Craighill contributed to this report.