The absence of a rigorous manifestation of NCSL within ICL can 
be traced to the dawn of the field. In the post-WWII period, NCSL was at the heart of the defendants’ challenge to the legality of the near-identical Charters governing the international military tribunals at Nuremberg and Tokyo. The Allied representatives drafting the Charters could have easily relied solely on the well-established constellation of war crimes to prosecute the WWII defendants. Instead, they opted to innovate and assert jurisdiction over two additional crimes, not theretofore codified: crimes against the peace (the crime of aggression in today’s lexicon) and crimes against humanity. War crimes, while deserving of opprobrium, did not fully capture the Nazi atrocities, which radiated outward in acts of aggression and penetrated inward as persecutory pogroms against compatriots.
be traced to the dawn of the field. In the post-WWII period, NCSL was at the heart of the defendants’ challenge to the legality of the near-identical Charters governing the international military tribunals at Nuremberg and Tokyo. The Allied representatives drafting the Charters could have easily relied solely on the well-established constellation of war crimes to prosecute the WWII defendants. Instead, they opted to innovate and assert jurisdiction over two additional crimes, not theretofore codified: crimes against the peace (the crime of aggression in today’s lexicon) and crimes against humanity. War crimes, while deserving of opprobrium, did not fully capture the Nazi atrocities, which radiated outward in acts of aggression and penetrated inward as persecutory pogroms against compatriots.The judges of the Nuremberg Tribunal (above left), in reasoning that was to be later echoed by their brethren on the Tokyo Tribunal, rejected the defense with a troika of analytical claims:
► The first move qualified the very application of the maxim, which the Tribunal argued is “not a limitation on sovereignty, but is in general a principle of justice.” This implied, of course, that states could override the principle in the collective exercise of their executive, legislative, or judicial powers.
► Second, having assigned the defense to the more flexible realm of equity, the Tribunal concluded that prosecution was justified, because the defendants could not have reasonably thought their conduct was lawful and it would be unjust to exonerate malefactors:
To assert that it is unjust to punish those who in defiance of treaties and assurances have attacked neighboring states without warning is obviously untrue, for in such circumstances, the attacker must know that he is doing wrong, and so far from it being unjust to punish him, it would be unjust if his wrong were allowed to go unpunished.
► Third, the Tribunal ruled that the Charter was an “expression of international law existing at the time of its creation.” With the NCSL defense neutralized, the Tribunal rendered judgment on all counts in the Indictment.
Proving that there is nothing new under the sun, these arguments are repeated in the modern ICL jurisprudence. Where states have failed to enact comprehensive ICL, judicial institutions have engaged in a full-scale refashioning of ICL through jurisprudence addressed to their own jurisdiction, the elements of international crimes, and applicable forms of responsibility. Along the way, courts have updated and expanded historical treaties and customary prohibitions, upset arrangements carefully negotiated between states, rejected political compromises made by states during multilateral drafting conferences, and added content to vaguely worded provisions that were conceived more as retrospective condemnations of past horrors than as detailed codes for prospective penal enforcement. By reviewing these cases, it is possible to construct a taxonomy of analytical claims made by tribunals adjudicating international criminal law to evade or neutralize the defense of NCSL. These arguments turn on a complex interplay of immorality, illegality, and criminality and depend in large part on the multiplicitous sources of international law.
Collectively, these cases -- in which defendants have been made subject to new or expanded 
criminal law rules -- have the potential to raise acute concerns about the rights of criminal defendants before today’s international criminal tribunals. Nonetheless, the methodology developed by the European Court of Human Rights (right) to enforce the articulation of the NCSL principle in its constitutive document, the European Convention for the Protection of Human Rights and Fundamental Freedoms, suggests that the NCSL jurisprudence has not compromised the fundamental fairness of ICL. Indeed, defendants were on sufficient notice of the foreseeability of such jurisprudential innovations in light of:
criminal law rules -- have the potential to raise acute concerns about the rights of criminal defendants before today’s international criminal tribunals. Nonetheless, the methodology developed by the European Court of Human Rights (right) to enforce the articulation of the NCSL principle in its constitutive document, the European Convention for the Protection of Human Rights and Fundamental Freedoms, suggests that the NCSL jurisprudence has not compromised the fundamental fairness of ICL. Indeed, defendants were on sufficient notice of the foreseeability of such jurisprudential innovations in light of:► extant domestic penal law;
► universal moral values expressed in international human rights law;
► developments in international humanitarian law and the circumstances in which it has been invoked; and
► other dramatic changes to the international order brought about in the post-World War II period.
I am exploring these ideas in a paper I posted here. I welcome your comments.
