Josh Rogin of Foreign Policy Magazine is reporting that a secret State Department memo says that the US government has concluded that the Syrian army used chemical weapons in the city of Homs last month.

A secret State Department cable has concluded that the Syrian military likely used chemical weapons against its own people in a deadly attack last month, The Cable has learned.

United States diplomats in Turkey conducted a previously undisclosed, intensive investigation into claims that Syrian President Bashar al-Assad used chemical weapons, and made what an Obama administration official who reviewed the cable called a "compelling case" that Assad's military forces had used a deadly form of poison gas.

The cable, signed by the U.S. consul general in Istanbul, Scott Frederic Kilner, and sent to State Department headquarters in Washington last week, outlined the results of the consulate's investigation into reports from inside Syria that chemical weapons had been used in the city of Homs on Dec. 23.

The consul general's report followed a series of interviews with activists, doctors, and defectors, in what the administration official said was one of the most comprehensive efforts the U.S. government has made to investigate claims by internal Syrian sources. The investigation included a meeting between the consulate staff and Mustafa al-Sheikh, a high-level defector who once was a major general in Assad's army and key official in the Syrian military's WMD program.

An Obama administration official who reviewed the document, which was classified at the "secret" level, detailed its contents to The Cable. "We can't definitely say 100 percent, but Syrian contacts made a compelling case that Agent 15 was used in Homs on Dec. 23," the official said.

The use of chemical weapons by the Assad regime would cross the "red line" President Barack Obama first established in an Aug. 20 statement. "We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. That would change my calculus. That would change my equation," Obama said.

To date, the administration has not initiated any major policy changes in response to the classified cable, but a Deputies Committee meeting of top administration officials is scheduled for this week.

Obama called it and not following through now would make him - and the US - appear impotent.

Rogin thinks that Assad is testing Obama's red lines. If that's the case, the dictator is feeling pretty good tonight. Giving more credence to that idea is the notion that the agent used was less catastrophic than some other chemical weapons:

"The symptoms of an incapacitating agent are temporary. If someone is exposed to BZ, they are likely to be confused, perhaps to hallucinate," said Amy Smithson, a senior fellow with the James Martin Center for Nonproliferation Studies. "While it is not good news that a chemical agent of any kind may have been used in the Syrian conflict, this Agent 15 is certainly on the less harmful end of the spectrum of chemical warfare agents believed to be in the Syrian arsenal."

The Cable spoke with two doctors who were on the scene in Homs on Dec. 23 and treated the victims. Both doctors said that the chemical weapon used in the attack may not have been Agent 15, but they are sure it was a chemical weapon, not a form of tear gas. The doctors attributed five deaths and approximately 100 instances of severe respiratory, nervous system, and gastrointestinal ailments to the poison gas.

Waiting to see if Assad will now launch a massive chemical weapons attack is apparently our strategy now. The goal line keeps moving and if Assad is smart, he will continue to launch these mini-WMD attacks daring the president to make good on his word.