How Does the Syria Situation Stack Up to the “Factors” that Justified Intervention in Kosovo?

As the Lawfare readership knows, the United States and its NATO allies relied on a series of factors in 1999 to argue that NATO’s intervention in Kosovo was legitimate. They used these factors to justify their intervention, though the factors served a second function of narrowing the ways in which others could use Kosovo as a precedent. But virtually no NATO state argued that the intervention was lawful, largely because the Charter does not legalize state uses of force in this context. We seem to be in a similar position now, after last night’s airstrikes in Syria.