Cooperating by Means of Collective Countermeasures? Examining States’ Obligations Regarding Grave Human Rights Violations

Abstract Human rights entail obligations owed by States to their own people and thus human rights violations, as such, appear to take place within the vertical relationship between a State and its residents. However, the past decades have seen a trend appear in international law towards recognition of a responsibility for third States to intervene in grave human rights crises and employ measures – such as collective countermeasures – to pressure violating States into compliance with their international human rights commitments. This article analyses whether Article 41(1) of the Draft articles on the Responsibility for Internationally Wrongful Acts ( ARSIWA ), and the duty to cooperate that it prescribes, entail an obligation for States to adopt collective countermeasures against other States, which are responsible for serious human rights violations. Thereby, it will identify the duty to cooperate as a due diligence obligation to argue that it imposes different requirements on different States.