New Article on the Legality of Signature Strikes

The article, which is available in draft form on SSRN, is entitled “‘One Hell of a Killing Machine’: Signature Strikes and International Law.”  It is forthcoming in the Journal of International Criminal Justice as part of a mini-symposium on targeted killing edited by Cornell’s Jens Ohlin.  Here is the abstract:

The vast majority of drone attacks conducted by the U.S. have been signature strikes – those that target “groups of men who bear certain signatures, or defining characteristics associated with terrorist activity, but whose identities aren’t known.” In 2010, for example, Reuters reported that of the 500 “militants” killed by drones between 2008 and 2010, only 8% were the kind “top-tier militant targets” or “mid-to-high-level organizers” whose identities could have been known prior to being killed. Similarly, in 2011, a U.S. official revealed that the U.S. had killed “twice as many ‘wanted terrorists’ in signature strikes than in personality strikes.”

Despite the U.S.’s intense reliance on signature strikes, scholars have paid almost no attention to their legality under international law. This article attempts to fill that lacuna. Section I explains why a signature strike must be justified under either international humanitarian law (IHL) or international human rights law (IHRL) even if the strike was a legitimate act of self-defence under Article 51 of the UN Charter. Section II explores the legality of signature strikes under IHL. It concludes that although some signature strikes clearly comply with the principle of distinction, others either violate that principle as a matter of law or require evidence concerning the target that the U.S. is unlikely to have prior to the attack. Section III then provides a similar analysis for IHRL, concluding that most of the signature strikes permitted by IHL – though certainly not all – would violate IHRL’s insistence that individuals cannot be arbitrarily deprived of their right to life.

I thoroughly enjoyed writing the article, which allowed me to put into academic form a number of ideas I’ve blogged about over the years — the relationship between the jus ad bellum and IHL/IHRL; the definition of armed conflict; what it means to be a member of an organized armed group; the scope of direct participation in hostilities; whether targeting in non-international armed conflict is geographically limited; and the best understanding of imminence under IHRL.  My guess is that both progressives and conservatives will find much to dislike.  Progressive won’t like my conclusion that a number of signature strikes are legal under either IHL or IHLR.  And conservatives won’t like my conclusion that many signature strikes violate both IHL and IHRL, with strikes in the latter category possibly amounting to crimes against humanity.

The deadline to go to press is quite soon, so I’m not sure if I can incorporate reader comments.  But, as always, I would deeply appreciate them.