One of the warnings most frequently issued by critics of NATO intervention in Libya was the danger this would pose by setting a precedent: if the West intervenes on behalf of Gaddafi’s opponents, then all across the Arab world, those who rise up to challenge their authoritarian rulers will expect similar outside support. This fear then fed widespread skepticism about the magnitude of the imminent threat to the population in Benghazi. Was an atrocity really about to take place or was this prediction merely being used as a pretext for intervention?

Subsequent events across the region have demonstrated that even if there were some pro-interventionists who imagined that Libya set a precedent, it has instead served if anything as a model not to be followed. Moreover, as warnings about the peril of chemical weapons in Syria are issued, the Obama administration seems to have drawn another lesson from Benghazi: an atrocity can only serve as a justification for military action after it has taken place.

So, those who are alarmed that the specter of WMD is being raised now in order to justify direct military involvement by the U.S. in Syria can take comfort in this thought: the deaths of tens of thousands of Syrians over the last two years has not been enough to draw America into another war. The only thing that would precipitate such involvement would be the deaths of thousands more and even then, these would have to occur over a period of days rather than months.

The lesson from Libya is that the U.S. will not intervene to prevent genocide; it will only intervene after genocide has already occurred. Indeed, the administration’s red line is merely that if Assad uses chemical weapons, there will be “consequences” — no one has actually spelled out what those consequences might be, so even in such an event we should not assume that military action will follow.