The civil war in Syria, one of the few lasting legacies of the Arab Spring, has been under way for more than two years. There has been substantial outside intervention in the war. The Iranians in particular, and the Russians to a lesser extent, have supported the Alawites under Bashar al Assad. The Saudis and some of the Gulf States have supported the Sunni insurgents in various ways. The Americans, Europeans and Israelis, however, have for the most part avoided involvement.
Last week the possibility of intervention increased. The Americans and Europeans have had no appetite for intervention after their experiences in Afghanistan, Iraq and Libya. At the same time, they have not wanted to be in a position where intervention was simply ruled out. Therefore, they identified a redline that, if crossed, would force them to reconsider intervention: the use of chemical weapons.
There were two reasons for this particular boundary. The first was that the United States and European states have a systemic aversion to the possession and usage of weapons of mass destruction in other countries. They see this ultimately as a threat to them, particularly if such weapons are in the hands of non-state users. But there was a more particular reason in Syria. No one thought that al Assad was reckless enough to use chemical weapons because they felt that his entire strategy depended on avoiding U.S. and European intervention, and that therefore he would never cross the redline. This was comforting to the Americans and Europeans because it allowed them to appear decisive while avoiding the risk of having to do anything.
However, in recent weeks, first the United Kingdom and France and then Israel and the United States asserted that the al Assad regime had used chemical weapons. No one could point to an incidence of massive deaths in Syria, and the evidence of usage was vague enough that no one was required to act immediately.