A state is responsible in international law for conduct in breach of its international obligations. Although the International Law Commission (ILC) began studying the subject in 1956, it was not until 2001 that it produced its final draft Articles (‘the Articles’) on the Responsibility of States for Internationally Wrongful Acts. The UN General Assembly circulated them in 2001. In A/RES/59/35 (2004), the General Assembly commended the draft Articles without prejudice to the question of any further action on them (such as adopting the Articles as a treaty), invited Members to comment on future action, and decided to consider the matter again in 2007.

The law of state responsibility is customary international law. Unlike state immunity, which has been developed largely by domestic legislation and domestic courts, state responsibility is pre-eminently an area of international law developed by state practice and international judgments, of which numerous examples are referred to in the ILC's Commentary on the Articles.