The “Unwilling or Unable” Standard for Self-Defense
One of the most remarkable aspects of how conservative U.S. scholars approach international law is their absolute certainty that the American position on extraordinarily difficult issues is always correct. Consider, for example, Jack Goldsmith’s articulation today of when the UN Charter permits the U.S. to use force in self-defense against non-state actors:
If the president is authorized to use force against a terrorist group by Congress, and if the U.N. Charter’s sovereignty concerns are overcome because the nation in question is unwilling or unable to address the group’s threat to the United States, and as long as the United States complies with jus in bello restrictions on targeting (distinction, proportionality, etc.), there is no further legal requirement.
Reading this, one would think it is patently obvious that international law accepts the “unwilling or unable” standard. Goldsmith does not bother to defend that position. (Ashley Deeks at least cites a couple of law reviews in defense of it, albeit one from 1958, in addition to — unsurprisingly — statements by American officials.)
Is the “unwilling or unable” standard the correct one? Perhaps — but that position needs to be the end of the analysis, not the beginning. After all, the ICJ does not accept the standard: the Court has consistently held that Article 51 of the UN Charter limits self-defensive acts against non-state actors to situations in which the non-state actor’s armed attacks are in some way imputable to the state whose territorial sovereignty is being violated. That was the ICJ’s position in Nicaragua, and the Court reaffirmed that position in both the Palestinian Wall advisory opinion and DRC vs. Congo. It is certainly possible to argue that the customary rules governing the use of force in self-defense have evolved to adopt the “unwilling or unable” standard. But that is a highly contentious and extraordinarily difficult question. As Tom Ruys has concluded in his magisterial study of Article 51 — a study that actually examines state practice and opinio juris concerning the use of armed force against non-state actors:
In the end, we must admit that this is an area which is characterized by significant legal uncertainty. De lege lata, the only thing that can be said about proportionate trans-border measures of self-defence against attacks by non-State actors in cases falling below the Nicaragua threshold is that they are ‘not unambiguously illegal’. De lege ferenda, we believe that customary law is evolving towards a different application of Article 51 UN Charter in relation to defensive action against a State – viz. coercive action that directly targets the State’s military or infrastructure – and defensive action within a State – viz. recourse to force against a non-State group present within the territory of another State.
Goldsmith exhibits no such tentativeness, perhaps because it is simply unthinkable to him that international law might limit the United States’ ability to use force in self-defense. Indeed, for too many American international-law scholars, particularly conservative ones, it is meaningless to distinguish between the lex lata and the lex ferenda — international law is simply whatever the U.S. says it is.