The Second Edition of "Defenses in Contemporary International Criminal Law" ventures farther into this uneasy territory than any previous work, offering a meticulous analysis of the case law in the post World War II Military Tribunals and the ad hoc tribunals for Rwanda and the Former Yugoslavia, with particular attention to the defenses developed, their rationales, and their origins in various municipal systems. It analyzes the defense provisions in the charters and statutes underlying these tribunals and the new International Criminal Court, while examining the first judgment in this field rendered by the Special Court for Sierra Leone, on June 20, 2007. The conceptual reach of this work includes not only the defenses recognized in the field's jurisprudence and scholarship (superior orders, duress, self-defense, insanity, necessity, mistake of law and fact, immunity of States), but also presents a strong case for the incorporation of genetic and neurobiological data into the functioning of certain defenses. Procedural mechanisms to invoke these defenses are also addressed.