Certainty of gas use expedited airstrikes

WASHINGTON — The United States, Britain and France opted to strike Syria for its apparent use of chemical weapons without waiting for a report from U.N. inspectors because they were convinced that the Assad government had used chlorine and sarin nerve gas against a rebel-held Damascus suburb, American officials said Saturday.

The allies also acted because of concerns that Russian and Syrian forces may already have tried to clean up important evidence in Douma, where more than 40 people died in last weekend’s attack, the officials said.

The three countries launched their missiles even as the fact-finding team from the Organization for the Prohibition of Chemical Weapons was in the Syrian capital and had been expected to head on Saturday to Douma.

Russia and Syria have denied that chemical weapons were used at all and said their own investigators had been to the area and found no trace of them. Those assertions have been denounced as lies by Western officials.

The West’s assessments of what happened April 7 in Douma rely mainly on open source information. That includes witness testimony, as well as video and photos shot by aid workers, victims of the attacks and unspecified additional intelligence about barrel bombs and chlorine canisters found in the aftermath.

Barrel bombs are large containers packed with fuel, explosives and scraps of metal, and British Prime Minister Theresa May said reports indicated the Syrian government had used one to deliver the chemicals.

The White House said doctors and aid organizations on the ground in Douma reported “the strong smell of chlorine and described symptoms consistent with exposure to sarin.” A senior administration official told reporters Saturday that while there was more publicly available evidence pointing to the use of chlorine, the U.S. has “significant information that also points to sarin use.”

The official did not elaborate on what that information entailed.