Does the Collective Self-Defense Justification Extend to Khorasan? If Not, Then Is There One?

I agree with Jens’ excellent post on the importance of the “unwilling or unable” standard to the US justification for legal strikes on non-state actors in Syria.  I agree this action may reveal state practice supporting (or rejecting) this legal justification.  I am curious whether the UK, France, or other states that may be participating in Syria strikes will embrace this theory. (I already know the Russians have roundly rejected this US justification). I also wonder whether this legal justification will weaken, as a policy matter, the ability of the US to effectively attack ISIS.

I do have one additional observation. Tacked on, almost as an afterthought, Ambassador Power’s letter notes that:

“In addition, the United States has initiated military actions against al-Qaida elements in Syria known as the Khorasan Group to address terrorist threats that they pose to the United States and our partners and allies.”

The vague wording of the letter about Khorasan (threats to “the United States and our partners and allies”) as compared to the pretty specific language about ISIS’s attacks on Iraq  (“ to end the continuing attacks on Iraq, to protect Iraqi citizens, “) suggests that Khorasan is not currently engaged in armed attacks on Iraq.  This means that the U.S. is making a much broader international law claim than for its attacks on ISIS.  The U.S. is attacking Khorasan because, like Al Qaeda, it is a terrorist threat to the U.S. itself.  But no actual armed attacks have yet occurred (as far as I know).

It is therefore worth noting whether more  states object to the attacks on Khorasan than on ISIS, because the Khorasan attacks have a weaker international legal justification. My guess is that objecting states like Russia will not bother distinguishing between the two. But it will be interesting to see whether US allies will refuse to join strikes on Khorasan, even if they are willing to strike ISIS in Syria.