It appears the Obama administration's efforts at persuasion are well underway. The administration plunged into weekend briefings -- classified and unclassified -- for lawmakers, and Obama challenged them to consider "what message will we send to a dictator" if he is allowed to kill hundreds of children with chemical weapons without suffering any retaliation.
At the same time, a senior State Department official said Secretary of State John Kerry spoke with Syrian Opposition Coalition President Ahmed Assi al-Jarba to underscore Obama's commitment to holding the Assad regime accountable for the alleged Aug. 21 attack.
While lawmakers are scheduled to return to work Sept. 9, officials said Saturday that it is possible the Senate might come back into session before then.
Obama said Friday he was considering "limited and narrow" steps to punish Assad, adding that U.S. national security interests are at stake. He pledged no U.S. combat troops on the ground in Syria, where a civil war has claimed more than 100,000 civilian lives.
In Syria, some rebels expressed unhappiness with the president, with one commander saying he did not consider Obama's decision to be a retreat.
"On the contrary, he will get the approval [from] Congress, and then the military action will have additional credibility," said Qassem Saadeddine. "Just because the strike was delayed by a few days doesn't mean it's not going to happen."
With Obama struggling to gain international backing for a strike, Putin urged him to reconsider his plans.
"We have to remember what has happened in the last decades, how many times the United States has been the initiator of armed conflict in different regions of the world, said Putin, a strong Assad ally. "Did this resolve even one problem?"
Even the administration's casualty estimate was grist for controversy.
The Syrian Observatory for Human Rights, an organization that monitors casualties in the country, said it has confirmed 502 deaths, nearly 1,000 fewer than the American intelligence assessment claimed.
Rami Abdel-Rahman, the head of the organization, said U.S. officials did not contact him about his efforts to collect information about the death toll in the alleged Aug. 21 attack.
"America works only with one part of the opposition, that is deep in propaganda," he said, and urged the Obama administration to release the information its estimate is based on.
Obama was buffeted, as well, by some lawmakers challenging his authority to strike Syria without congressional approval, and also by others who urged him to intervene more forcefully than he has signaled he will.
In the hours before Obama's Rose Garden announcement, top advisers joined him at the White House.
Vice President Biden, who had planned a holiday weekend at home in Delaware, was among them. So, too, were Defense Secretary Chuck Hagel and Secretary of State John Kerry.
In the famously flammable Middle East, Israel readied for the possible outbreak of hostilities. The Israeli military disclosed it has deployed its "Iron Dome" missile defense battery in the Tel Aviv area to protect civilians from any possible attack from next-door Syria or any of its allies.
Missile defenses were deployed in the northern part of the country several days ago, and large crowds have been gathering at gas-mask distribution centers to pick up protection kits.