The regime of embattled Syrian dictator Bashar Assad is actively working to enlarge its arsenal of chemical weapons, U.S. officials tell Danger Room. Assad’s operatives have tried repeatedly in recent months to buy up the precursor chemicals for deadly nerve agents like sarin, even as his country plunges further and further into a civil war. The U.S. and its allies have been able to block many of these sales. But that still leaves Assad’s scientists with hundreds of metric tons of dangerous chemicals that could be turned into some of the world’s most gruesome weapons.

“Assad is weathering everything the rebels throw at him. Business is continuing as usual,” one U.S. official privy to intelligence on Syria says. “They’ve been busy little bees.”

Back in July, the Assad regime publicly warned that it might just use chemical weapons to stop “external” forces from interfering in its bloody civil war. American policy-makers became deeply concerned that Damascus just might follow through on the threats. Since the July announcement, however, the world community — including Assad’s allies — have made it clear to Damascus that unleashing weapons of mass destruction was unacceptable. The message appears to have gotten through to Assad’s cadre, at least for now. Talk of direct U.S. intervention in Syria has largely subsided.