In August 2012, Obama was asked about what could lead him to use military force in Syria: “We have been very clear to the Assad regime,” he said, “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.” In the course of a presidency, a U.S. president says millions of words in public. You never know which of those words end up cementing a certain impression. For Obama, one of those phrases would be “red line.”
