Obama warns Assad chemical weapons are red line for US

US President Barack Obama told an unscheduled White House briefing Monday:  "A red line for us is (if) we see a whole bunch of chemical weapons moving around, or being utilized.” He said “At this point” he had not ordered US military engagement in Syria, but “that would change my calculus.”
The use of such weapons of mass destruction, which Syria has, would widen the conflict considerably. "It doesn't just include Syria. It would concern allies in the region, including Israel, and it would concern us," Obama said.

See DEBKAfile report of Aug. 17