As readers of Lawfare know, a growing number of States believe that use of force in self-defense against a non-state actor on the territory of a third State, without the consent of that third State, may be lawful under international law if the non-state actor has undertaken an armed attack against the State and the third State is itself unwilling or unable to address the threat posed by the non-state actor. In what follows, we provide an up-to-date list of the States that...