AP White House Correspondent
WASHINGTON (AP) -- President Barack Obama on Thursday prepared for the possibility of launching unilateral American military action against Syria within days as Britain opted out in a stunning vote by Parliament. Facing skepticism at home, too, the administration shared intelligence with lawmakers aimed at convincing them the Syrian government used chemical weapons against its people and must be punished.
Despite roadblocks in forming an international coalition, Obama appeared undeterred and advisers said he would be willing to retaliate against Syria on his own.
"The president of the United States is elected with the duty to protect the national security interests in the United States of America," White House spokesman Josh Earnest said.
Even before the vote in London, the U.S. was preparing to act without formal authorization from the United Nations, where Russia has blocked efforts to seek a resolution authorizing the use of force, or from Capitol Hill. But the U.S. had expected Britain, a major ally, to join in the effort.
Top U.S. officials spoke with certain lawmakers for more than 90 minutes in a teleconference Thursday evening to explain why they believe Bashar Assad's government was the culprit in a suspected chemical attack last week. Lawmakers from both parties have been pressing Obama to provide a legal rationale for military action, to specify objectives and to lay out a firm case linking Assad to the attack.
Afterward, the House Democratic leader, Rep. Nancy Pelosi of California, pointedly sided with Republican Speaker John Boehner of Ohio in urging the administration to do more to engage with Congress on the matter, even as she expressed "my appreciation for the measured, targeted and limited approach the president may be considering."
She said in a statement she agreed with Boehner and other lawmakers who say the administration needs to consult more with "all members of Congress" -- a reference to the limited circle briefed Thursday night -- and provide "additional transparency into the decision-making process."
The high-level officials who spoke to the lawmakers offered more details of the suspected chemical attack and their firm conviction that the Syrian government was to blame -- but little new evidence backing up that conviction. It remained to be seen whether any skeptics were swayed by the call, given the expectation in advance that officials would hold back classified information to protect intelligence sources and methods.
The officials told lawmakers 1,300 men, women and children died in the attack, said Rep. C.A. Dutch Ruppersberger of Maryland, top Democrat on the House Intelligence Committee. That's a far higher death toll than has been reported; the humanitarian group Doctors Without Borders says the attack outside Damascus killed 355.
A number of lawmakers raised questions in the briefing about how the administration would finance a military operation as the Pentagon is grappling with automatic spending cuts and reduced budgets.
Sen. Jim Inhofe of Oklahoma, the top Republican on the Armed Services Committee and a participant on the call, said in a statement that the administration presented a "broad range of options" for dealing with Syria but failed to offer a single plan, timeline, strategy or explanation of how it would pay for any military operation.
"The main thing was that they have no doubt that Assad's forces used chemical weapons," New York Rep. Eliot Engel, top Democrat on the House Foreign Affairs Committee and a supporter of Obama's course, said after the briefing.
Even so, he said the officials did not provide much new evidence of that.
"They said they have (intercepted) some discussions and some indications from a high-level official," he said, and that they possess intelligence showing material being moved in advance of the attack.
An intelligence report similar to the findings shared with lawmakers Thursday night is expected to be released publicly on Friday.
In London, Prime Minister David Cameron argued a military strike would be legal on humanitarian grounds. But he faced deep pressure from lawmakers and had already promised not to undertake military action until a U.N. chemical weapons team on the ground in Syria released its findings about the Aug. 21 attack.
The prime minister said in terse comments after the vote that while he believes in a "tough response" to the use of chemical weapons, he would respect the will of the House of Commons.
Caitlin Hayden, Obama's National Security Council spokeswoman, said the U.S. would continue to consult with Britain but Obama would make decisions based on "the best interests of the United States."