"I have, at this point, not ordered military engagement in the situation. But the point that you made about chemical and biological weapons is critical. That’s an issue that doesn’t just concern Syria; it concerns our close allies in the region, including Israel. It concerns us. We cannot have a situation where chemical or biological weapons are falling into the hands of the wrong people.
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.
Q So you're confident it’s somehow under -- it's safe?
THE PRESIDENT: In a situation this volatile, I wouldn’t say that I am absolutely confident. What I’m saying is we’re monitoring that situation very carefully. We have put together a range of contingency plans. We have communicated in no uncertain terms with every player in the region that that’s a red line for us and that there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons. That would change my calculations significantly."
(whitehouse.gov, remarks to the White House Press Corps, 20 augustus 2012)