Delaying what had appeared to be an imminent strike, President Barack Obama abruptly announced Saturday he will seek congressional approval before launching any military action meant to punish Syria for its alleged use of chemical weapons in an attack that killed hundreds.
With Navy ships in the Mediterranean Sea ready to strike, Obama said he had decided the United States should take military action, but also determined "our country will be better off" if Congress renders its own opinion.
At the same time, he challenged lawmakers to consider "what message will we send to a dictator" if he is allowed to killed hundreds of children with chemical weapons without suffering any retaliation.
Lawmakers will return to session on Sept. 9.
U.N. inspectors arrived in Amsterdam after spending several days in Syria collecting soil samples and interviewing victims of an attack last week in the Damascus suburbs. Officials said it could me more than a week before their final report is complete.
It seemed unlikely Obama would wait that long to order any strike, given the flotilla of U.S. warships equipped with cruise missiles and massed in the Mediterranean; Friday's release of a declassified U.S. intelligence assessment saying Assad's chemical weapons killed 1,429 civilians; and an intensifying round of briefings for lawmakers clamoring for information.
The president said Friday that he was considering "limited and narrow" steps to punish Assad for the attack, adding that U.S. national security interests were 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.
Even so, any military strike had the potential to spark unpredictable consequences, and Assad has had several days to redeploy his own military assets as Obama consulted with foreign leaders and members of Congress.
With Obama struggling to gain international backing for a strike, Russian President Vladimir Putin urged him to reconsider his plans, saying he speaking to him not as a president but as the recipient of a Nobel Peace Prize.
"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 he was not contacted by U.S. officials about his efforts to collect information about the death toll in the Aug. 21 attacks.
"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.
The White House arranged a pair of unclassified briefings by phone Saturday afternoon, one for Senate Republicans, the other for Democrats.
It also announced it would provide a classified update on Sunday in the Capitol for lawmakers who wished to fly to the capital and attend. Lawmakers have been on a summer break for four weeks, and are not due to return to session until Sept. 9.
Vice President Joseph Biden, who had planned a holiday weekend at home in Delaware, was at the White House. So, too, were Defense Secretary Chuck Hagel, Secretary of State John Kerry and other top administration officials.
Assad's government claims that rebels were responsible for the attack last week in the Damascus suburbs, but it appeared resigned to a U.S. military strike. State television broadcast images of the weapons of war and soldiers training, over a background of martial music.
"We are anticipating it starting tonight, since the inspectors have left, but we don't really know," said a 23-year-old pharmacy student who provided only her first name, Nour. "Just in case, we stocked up on some water and food," she said, adding that the building where she lives has laid in a supply of pillows, blankets and a first aid kit with basic medications.
In the famously flammable Middle East, Israel readied for the possible outbreak of hostilities. The Israeli military disclosed it has deployed an "Iron Dome" missile defense battery in the Tel Aviv area to protect civilians from any possible missile 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.
Associated Press writers Julie Pace, Josh Lederman, Matthew Lee and Kimberly Dozier in Washington; Zeina Karam, Yasmine Saker and Karin Laub in Beirut; and Geir Mouslon in Berlin contributed to this report.