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.

Ashley S. Deeks, How Does the Syria Situation Stack Up to the “Factors” that Justified Intervention in Kosovo?, Lawfare (April 7, 2017).