It appears that the United States conducted an airstrike in Libya yesterday, targeting and killing Mokhtar Belmokhtar--a notorious Algerian terrorist who was once a member of GIA and GSPC, continued as a key leader for GSPC after it affiliated with al Qaeda and became AQIM, and most recently broke with AQIM by going independent with his own organization (known by a variety of names, including--quite seriously--the "Signed in Blood Brigade"). He and his group were especially well-known for a horrific attack on an Algerian gas plant in 2013, which resulted in the death of some 38 hostages.
Are there any novel issues here from a legal perspective? The Libyan government has issued a statement indicating that it consented to this use of force on its territory, so there's nothing particularly interesting to see here on the U.N. Charter front (unless you are among those who take the view that states cannot give such consent). But what about AUMF issues, given that Belmokhtar's immediate organizational tie is to an obscure entity not among those that have been publicly identified by the administration as falling within the scope of the 2001 AUMF (as an associated force of al Qaeda engaged in hostilities against the United States or its allies)?
Based on some of the preliminary public statements from DOD officials, it may be that the controlling AUMF theory here is not that Belmokhtar's current group (Signed in Blood) or his prior group (AQIM) constitute associated forces the members of whom are currently eligible for targeting under the AUMF, but rather that Belmokhtar as an individual remained part-and-parcel of al Qaeda itself. That said, all doors were left open by this statement from a spokesman for the Chairman of the Joint Chiefs of Staff:
“Belmokhtar has a long history of leading terrorist activities as a member of AQIM, is the operational leader of the al Qaeda-associated al Murabitun organization in northwest Africa, and maintains his personal allegiance to al Qaeda,” Thomas said in a statement, referring to al-Qaeda in the Islamic Maghreb.
Though both group and individual ties are mentioned here, I think that given the emphasis on the personal-allegiance theory we can't quite infer that DOD is now categorizing all of AQIM or all of Signed in Blood as falling within the AUMF's scope. Then again, it is worth noting Eric Schmitt's observation in the Times that Belmokhtar's "direct operational ties to al Qaeda...have lessened". In short, the circumstances raise interesting questions about what it means to have the sort of individual ties to al Qaeda that would justify action under the AUMF; we focus a lot on parsing what it takes to make it as an associated force, but outside the context of GTMO litigation we rarely see discussion of the individual-member question.
A final note: this attack was carried out by manned aircraft--F-15s, to be precise. A useful reminder that it is a mistake to analyze the use of lethal force for counterterrorism purposes exclusively through the "drone" lens.