Book World: 'Red lines' in conflict zones: When they work and when they fail David Bosco, The Washington Post Dec. 31, 2020 FacebookTwitterEmail A Red Line in the Sand By David A. Andelman - - - On Aug. 20, 2012, at the tail end of a news conference that focused mostly on domestic politics, President Barack Obama fielded a question about the expanding civil war in Syria. The president condemned the violence by the regime of Bashar al-Assad and detailed his administration's efforts to provide humanitarian aid. He noted pointedly that he had not ordered military involvement, but he did add a caveat. Chemical weapons were a "red line," and their use "would change my calculations significantly." Almost exactly a year later, Syrian government forces bombarded a Damascus neighborhood with a nerve agent.