Defending 'Terrorism': Justifications and Excuses for Terrorism in International Criminal Law

The first part of this article outlines the purported causes of terrorism advanced in the UN General Assembly since the 1970s, and the contrary views of States on whether these causes ought to justify or excuse terrorist violence - particularly self-determination or national liberation violence. The second part examines how a limited range of justifications for any new international crime of terrorism could be accommodated by individual defences in international criminal law (including self-defence, and duress/necessity). It then proposes that non-State group actors accused of terrorist crimes should be entitled to plead 'circumstances precluding wrongfulness', drawn analogously from the law of State responsibility. While a narrow class of terrorist acts may be excused by individual or group defences, some acts considered justifiable may still fall outside the scope of defences. To maintain the law's legitimacy, the final part argues that some crimes of terrorism could be regarded as 'illegal but justifiable' (or at least, excusable) in stringently limited, objectively verifiable circumstances, possibly under the rubric of a 'collective defence of human rights'.