The ISIS Crisis and the Development of International Humanitarian Law

Johan D. van der Vyver analyzes efforts to respond to acts of violence committed by ISIL and its successor, ISIS. One such response is the 'unwilling or unable' paradigm under which the armed forces of State A can take military action against terrorist groups located in State B if the government of State B is either unwilling or unable to prevent its territory from being to launch attacks. The paradigm has been used to justify airstrikes by the United States against al-Qaeda and ISIS targets in Iraq and Syria. Professor van der Vyver argues that the paradigm does not fit the conditions of self-defense under the U.N. Charter or the essential objectives of humanitarian intervention and concludes that the unwilling or unable rationale is a new norm of jus ad bellum in the making.