WASHINGTON — The massacre of more than 100 civilians, many of them children, in Syria over the weekend has presented Mitt Romney with a new opportunity to sound a familiar theme: that President Obama’s foreign policy is feckless and lacking in courage.
Mr. Romney, the presumptive Republican presidential nominee, condemned Mr. Obama on Tuesday for a “policy of paralysis” toward Syria that he said had allowed President Bashar al-Assad to “slaughter 10,000 individuals.”
But Mr. Romney’s own prescriptions for ending the mounting death toll in Syria have been less definitive than his denunciations of the president.
He called for the United States to “work with partners to organize and arm Syrian opposition groups so they can defend themselves” — a policy that goes somewhat further than Mr. Obama’s but falls short of the airstrikes advocated by Republicans like Senators John McCain of Arizona and Lindsey Graham of South Carolina.
The White House has rejected arming rebel groups, saying it does not know enough about them and does not want to “further militarize the situation.” But the question of whether to arm the Syrian opposition has also split Republicans.
Such caution, from both the incumbent and the challenger, reflects the complexities of the Syrian uprising as well as the recognition that Americans have little appetite for another large-scale military engagement.
Even human rights groups are not demanding intervention.
“No human rights organization wants to criticize the administration for failing to do something we haven’t yet asked them to do,” said Tom Malinowski, the head of the Washington office of Human Rights Watch. “We see more complexity and risk in Syria because of the sectarian dimension and the weakness of the opposition.”
That does not mean Mr. Obama has escaped criticism for his cautious approach to Syria. Some analysts said he had missed a chance early in the uprising to push out Mr. Assad, calling instead for an orderly political transition. Other critics said the White House had also failed to play a later leadership role, even as it announced Tuesday that it had expelled Syria’s top diplomat to the United States.
That announcement, said the chairwoman of the House Foreign Affairs Committee, Representative Ileana Ros-Lehtinen, should have come before similar moves by countries like Britain, France and Germany. “The U.S. should have taken the lead in expelling Syrian regime officials,” Ms. Ros-Lehtinen, a Republican from Florida, said in a statement.
Mr. Malinowski said that “complexity can’t be an argument for paralysis.” Even if the White House has valid reasons to avoid intervening, he said, it is useful to raise the possibility of military action — as the chairman of the Joint Chiefs of Staff, Gen. Martin E. Dempsey, did in an interview Monday — if only to prod the diplomatic process.
Still, proponents of a harder line acknowledge that there is little support in either party for military intervention. Despite the support for intervention in Libya voiced by Mr. Graham, Mr. McCain and Senator Joseph I. Lieberman, the Connecticut independent, Republicans pummeled Mr. Obama when the United States did join NATO in acting there.
“Maybe the kids will make the difference,” Mr. Graham said in an interview, referring to the killings on Friday in the Houla area of central Syria. “We live in a visual world. When you see the slaughter of 30 children, it reminds us of who we are.”
Mr. Graham said that he would push Mr. Obama and Mr. Romney to stiffen their responses. He said he favored imposing a no-flight and no-drive perimeter around civilian centers and gauging where a military intervention should go from there.
Mr. Romney has not embraced airstrikes — in part, one of his advisers said, because Syria, unlike Libya, does not have a long, isolated highway that NATO could bomb to cut off the government’s forces. But Mr. Romney believes arming opposition groups is critical to asserting a “robust American leadership role,” said Richard Williamson, a foreign policy adviser to his campaign.
From the start of the uprising, Mr. Williamson said, Mr. Obama’s response has been muted and “slow on the draw,” even after horrendous abuses by the Assad government. While Mr. Williamson acknowledged a risk of bad elements among the rebels, he said: “You could help the opposition unify. Instead we’re subcontracting it to Kofi Annan.”
Mr. Romney marked Memorial Day with Mr. McCain, a fervent supporter of arming the rebels. But the chairman of the House intelligence committee, Representative Mike Rogers, Republican of Michigan, said he opposed it because “there are some bad actors there as well.”
The White House press secretary, Jay Carney, said arming the opposition in Syria could “lead to greater chaos.” While they oppose arming opposition groups, administration officials have said the United States is ready to share intelligence with countries that have signaled they will ship weapons, to avoid supplying militants affiliated with Al Qaeda or other terrorist organizations.
A spokesman for the Obama campaign, Ben LaBolt, said Mr. Romney offered “nothing but tough talk, a commitment to endless wars in Iraq and Afghanistan, and a rudderless foreign policy agenda.”