Answering a reporter’s question if bombing Syria is needed in order to preserve his credibility since he was the one who set a red line, President Obama replied: “First of all, I didn't set a red line. The world set a red line. The world set a red line when governments representing 98 percent of the world's population said the use of chemical weapons are abhorrent and passed a treaty forbidding their use even when countries are engaged in war. Congress set a red line when it ratified that treaty..."
It is true that international law and treaties have prohibited the use of certain weapons nearly a century ago. But UN Charter, the backbone of international law, also had established the proper response to any breach of these treaties. Outside the doctrine of self-defense from an imminent threat, no nation should attack another UN member state without authorization of the UN Security Council (UNSC). If nations were to act unilaterally, would U.S. leaders ratify a treaty that would allow, say the Soviet Union or China, to bomb the U.S. for actually using illegal weapons in Vietnam and other places?
Available at: http://works.bepress.com/souaiaia/23/