Three days before the rockets fell outside Damascus, a team of Syrian specialists gathered in the northern suburb of Adra for a task that U.S. officials say had become routine in the third year of the country’s civil conflict: filling warheads with deadly chemicals to kill Syrian rebels.
The preparations, as described by U.S. intelligence analysts, continued from Aug. 18 until just after midnight on Aug. 21, when the projectiles were loaded into rocket launchers behind the government’s defensive lines. Then, at 2:30 a.m., a half-dozen densely populated neighborhoods were jolted awake by a series of explosions, followed by an oozing blanket of suffocating gas.
Unknown to Syrian officials, U.S. spy agencies recorded each step in the alleged chemical attack, from the extensive preparations to the launching of rockets to the after-action assessments by Syrian officials. Those records and intercepts would become the core of the Obama administration’s evidentiary case linking the Syrian government to what one official called an “indiscriminate, inconceivable horror” — the use of outlawed toxins to kill nearly 1,500 civilians, including at least 426 children.
Pulling back the curtain on some of the United States’ most sensitive collection efforts, the Obama administration released on Friday its long-awaited intelligence assessment of the Aug. 21 event, explaining in rare detail the basis for its claim that Syria was behind the release of deadly gas, the grisly effects of which have been documented in more than 100 amateur videos.
The four-page assessment and accompanying map revealed for the first time how communications intercepts and satellite imagery picked up key decisions and actions on the ground.