CAIRO — The leaders of the Arab world blamed the Syrian government on Tuesday for a chemical weapons attack that killed hundreds of people last week, but declined to back a retaliatory military strike, denying the United States the kind of broad regional support that US governments have generally sought for interventions in the Middle East.
While the Obama administration has robust European backing and quiet Arab support for a strike on Syria, the position of the Arab League and the inability to win a UN mandate complicates the legal and diplomatic case for the White House. The Obama administration has yet to make clear if it has intelligence linking the Syrian government to the use of chemical weapons, though the White House said there was no doubt that had occurred.
Taken together, this leaves the Obama administration on the verge of ordering military action without the kind of broad political, legal, or diplomatic support the United States has typically sought before military interventions in the volatile region, as in Libya in 2011.
Administration officials have declined to spell out the legal justification that President Obama would use in ordering a strike, beyond saying the large-scale use of chemical weapons violates international norms. But officials said the president could draw on a range of treaties and statutes, from the Geneva Conventions to the Chemical Weapons Convention.
Obama, they said, could also cite the need to protect a vulnerable population, as his Democratic predecessor, Bill Clinton, did in ordering NATO's 78-day air campaign on Kosovo in 1999. Or he could invoke the principle of "responsibility to protect," which some officials cited to justify the US-led bombing campaign in Libya.
"There is no doubt here that chemical weapons were used on a massive scale on Aug. 21 outside of Damascus," said the White House spokesman, Jay Carney. "There is also very little doubt, and should be no doubt for anyone who approaches this logically, that the Syrian regime is responsible."
A number of nations in Europe and the Middle East, along with several humanitarian organizations, have joined the United States in the assessment about last week's attack.
With the specter of faulty intelligence assessments before the Iraq war still hanging over US decision making, and with opinion polls showing that only a small fraction of the US public supports military intervention in Syria, some officials in Washington realize that there needs to be a public presentation making the case for war.
A statement by the Arab League on Tuesday added to the uncertainty, underscoring the complexity of the regional landscape, where years of turmoil have set off fierce sectarian fighting and a tidal wave of refugees and left many fearful that a US strike would further inflame tensions.
Leaders of the Arab world are divided over a potential Western airstrike against Syria in retaliation for the use of chemical weapons, caught between public hostility to intervention and a tangle of shifting rivalries and allegiances.
With the majority of Arabs emotionally opposed to any Western military action in the region no matter how humanitarian the cause, no Arab nation or leader has publicly endorsed such a step. In the region, only Turkey has pledged to support intervention.
Behind the scenes at least two closely allied Arab heavyweights, Egypt and Saudi Arabia, might be split over which enemy poses the greater immediate threat to their regional interests: the Sunni Islamists who dominate the Syrian rebels, or the Shi'ite Iranian backers of Syria's president, Bashar Assad.
The Arab League, a regional diplomatic forum that has expelled Assad’s government, said in its statement that it holds “the Syrian regime responsible for this heinous crime,” but appeared to suggest that the specific perpetrators were not yet known and should be brought to international justice.
The league called on the UN Security Council to "overcome the disagreements between its members" in order to "take the necessary deterring measures against the perpetrators of this crime, whose responsibility falls on the Syrian regime," and to end the other abuses.
Obama administration officials, who asked not to be identified, asserted that they were satisfied with the Arab League statement since it assigned responsibility to Assad's government for the chemical attack, was issued quickly, and called on Security Council members to overcome their differences.
"This was a big diplomatic step forward in laying the groundwork for actions the president might choose, and required days of aggressive diplomacy to avoid delay," a senior administration official said Tuesday night.