A legal defense is the offering of substantive and procedural obstacles to the prosecution of a crime in a court of law. Regarding crimes of genocide, war crimes, and crimes against humanity, the first issue to consider is whether a particular defense or defense strategy can be sustained according to the general principles of international criminal law. Article 31 of the Rome Statute of the International Criminal Court (ICC) is significant in this regard. This statute is based on a mixture of common and civil law principles, as well as provisions drawn from comparative criminal law, and refers to "grounds for excluding criminal responsibility." However, Article 31 of the ICC statute accentuates the civil law dimension of this concept by refraining from the common law practice of distinguishing between certain types of defenses.

Significantly, the ICC statute does not differentiate between justifications and excuses offered in...