WASHINGTON — U.S. intervention in Syria won't have the support of key ally Britain after a historic vote by Parliament on Thursday to reject any military action to deter the use of chemical weapons by President Bashar Assad's regime.
The move seriously undermines President Barack Obama's ability to build an international coalition in support of missile strikes against Syria.
But the U.S. appeared undeterred and prepared to go it alone if need be. White House National Security Council spokeswoman Caitlin Hayden said that Obama's decision-making will be guided by what he deems to be in the country's best interests.
"He believes that there are core interests at stake for the United States and that countries who violate international norms regarding chemical weapons need to be held accountable," she said.
The British House of Commons voted in special session Thursday against participating in any attack on Syria, 285-272. Members of Parliament also voted down a motion to support military action even if United Nations inspectors confirm that Assad's regime had used chemical weapons against civilians.
Prime Minister David Cameron said he'd respect the decision.
"It is clear to me that the British Parliament, reflecting the will of the British people, does not want military action," Cameron said.
Another European ally, France, also appeared to back off initial support for a speedy intervention, instead pushing for a delay on action pending the findings of the U.N. inspection team. The inspectors were expected to wrap up their work in Syria by Saturday and head back to New York to begin a reconstruction of the apparent poison gas attack on Aug. 21, which killed hundreds of civilians and injured thousands more in the suburbs of Damascus.
French President Francois Hollande had only days ago vowed to punish Assad for the use of chemical weapons. By Thursday, however, he had eased his stance. A French government spokeswoman was quoted as saying, "Before acting, we need proof."
Obama called German Chancellor Angela Merkel on Thursday, continuing a series of calls to leaders around the globe about the situation in Syria.
As Washington appeared to move closer to a decision about military action, the memory of the fallout from the faulty intelligence used to justify the invasion of Iraq a decade ago hovered over the current debate.
"With so many Americans skeptical about the wisdom of acting militarily, a close ally's skepticism will embolden critics," said Jon Alterman, a former State Department senior official involved with Iraq war planning under President George W. Bush. "For countries reluctant to back military action, this will strengthen their reluctance. For those who wish to isolate the United States, and there are several, this is a gift."
But White House spokesman Josh Earnest pushed back against any similarities between Syria and Iraq.
"I think that there are some very important differences," he said. "What we saw in that circumstance was an administration that was searching high and low to produce evidence to justify a military invasion, an open-ended military invasion of another country, with the final goal being regime change. . What we have seen here, tragically, is a preponderance of evidence available in the public domain that the Assad regime used chemical weapons against innocent civilians."
Earnest said Obama believes there is a "compressed time frame in which a decision needed to be made" about whether and when to attack.
The Obama administration remains adamant that the Syrian government is responsible for the apparent Aug. 21 chemical weapons attack. Officials briefed key lawmakers Thursday night on details of an intelligence report about the attack that is said to lay the blame on Syrian officials; the administration is developing an unclassified version for release to the public.
It will be released by the end of the week, but Earnest said that not all the details will be released because they are classified.