Good thing nothing much happened while I was away on summer vacation… So as I wrote
here last spring, there’s no clear basis under international law for a U.S. use of force in Syria – no UN Security Council resolution, and no apparent claim at this stage that the United States is acting in self-defense. The only theory of legality in play seems to be the one put forward by the British government, right before Parliament voted to reject the use of force in Syria. Namely, that force may be justified as part of an emergent customary norm permitting humanitarian intervention (see, e.g., NATO intervention in Kosovo).
The statement from the UK Prime Minister’s Office says a state may take “exceptional measures in order to alleviate the scale of the overwhelming humanitarian catastrophe in Syria by deterring and disrupting the further use of chemical weapons by the Syrian regime. Such a legal basis is available, under the doctrine of humanitarian intervention, provided” a set of conditions hold. Those conditions: (1) “convincing evidence, generally accepted by the international community as a whole, of extreme humanitarian distress on a large scale, requiring immediate and urgent relief;” (2) it is “objectively clear that there is no practicable alternative to the use of force if lives are to be saved;” (3) the force used is “necessary and proportionate to the aim of relief of humanitarian need…”
But it just can’t support U.S. action here. Here’s why.
