Nearly 80 percent of those surveyed said the Obama administration had not clearly explained its objectives in Syria, while 69 percent said Mr. Obama should not go ahead with a strike without Congressional authorization. Fifty-six percent of people said they disapproved of how the president has handled Syria, while 33 percent approved.

The poll was conducted before the Russia floated its proposal, and while the proposal may yet founder for a variety of reasons, it was clear in follow-up interviews with the Americans surveyed that they were latching on to any solutions that would avert a military strike.

“I just saw on the Internet that the Russians said they would take Syria’s weapons of mass destruction if they would give them up, and destroy them,” said Jim Ploskunak, 68, a retired manager of a foundry who lives in Charlo, Mont. “That’s better than war.”

The resistance to getting involved in Syria is deep. While 75 percent of people think that Mr. Assad’s forces used chemical weapons, 74 percent say they oppose supplying rebel forces in Syria with conventional arms. The Obama administration reluctantly adopted that policy on a covert basis in June after it concluded that Syrian forces had used chemical weapons on a smaller scale in previous attacks.

“What our government needs to do is work on keeping our country safe,” said Jeanette Baskin, a social worker on Staten Island. “We invest all this money in foreign countries and fixing their problems, and this country is falling apart. Makes no sense.”

Ms. Baskin, 69, who said she was neither a Democrat nor a Republican, dismissed Mr. Obama’s reassurances that a strike against Syria would be limited and specific, citing the September 2001 terrorist attacks.

“Whoever did the World Trade Center and those other places had specific targets in mind,” she said. “Did that make it right?”