In 1998 120 nations decided to create an International Criminal Court.  This initiative did not come out of the blue, but was the culmination of a trend running through most of the 20th Century.

By the middle of the 20th Century, it was not an uncommon practice to let national courts of law try suspected war criminals after an armed conflict had taken place.  Nonetheless, when the International Military Tribunal was created for the Nuremberg Trials after the end of the Second World War in 1945, it was in many ways a completely new thing, and it had a lasting effect on international humanitarian law.

The tribunal's jurisdiction included, basically (q.v. Nuremberg Trials), (a) Crimes against Peace; (b) War Crimes, and; (c) Crimes against Humanity.  The accused claimed that those definitions were only invented in 1945 and that because of this the accused should not be punished for past transgressions (nulla poena sine lege).  The tribunal rejected this claim, but from a legal standpoint this was a somewhat controversial verdict.  The controversy was not whether the accused could be tried for war crimes—as stated above, this was in many ways common practice in the context of national law—nor was the question of crimes against peace the major issue, even though the tribunal's argument was arguably a bit weak, based almost solely on the Briand-Kellogg Pact.  No, the issue was with the crimes against humanity.  By definition, states could be guilty of crimes against humanity against any civilian population, including their own, and in 1945 the general understanding had been that a state was pretty much in its legal right to do whatever it very well pleased with its own population—as opposed to to aliens who enjoyed the recognized protection of international law.  The unmistakable statement that this was not the case was new and startling to the humanitarian lawyers.

The tribunal moderated themselves, however.  In the original wording, the accused could be held individually responsible for crimes against humanity both before and during the war, but in a statement the tribunal restricted the scope: “To constitute crimes against humanity, the acts relied on before the outbreak of the war must have been in execution of, or in connection with, any crime within the jurisdiction of the Tribunal. …The Tribunal therefore cannot make a general declaration that the acts before 1939 were crimes against humanity”  Still, the charter of the tribunal became precedential, and in its first session in 1946 the General Assembly of the United Nations took note of it and the fact that it had been used also in the International Military Tribunal for the Far East, and it affirmed the principles of the charter and directed the Committee on the codification of international law—which had been previously established—to formulate an international criminal code based on the principles of the tribunal.

In the Geneva Convention of 1949 a new concept was introduced; that of "grave breaches" of the convention in which case any contracting party's national courts of law—not just the courts of the citizens offended—have the jurisdiction to prosecute and condemn offenders:

“The High Contracting Parties undertake to enact any legislation necessary to provide effective penal sanctions for persons committing, or ordering to be committed, any of the grave breaches of the present Convention defined in the following Article. …Grave breaches…shall be those involving any of the following acts, if committed against persons or property protected by the Convention: wilful killing, torture or inhuman treatment, including biological experiments, wilfully causing great suffering or serious injury to body or health, and extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly. …No High Contracting Party shall be allowed to absolve itself…of any liability incurred by itself or by another High Contracting Party in respect of breaches”

Then for a long time nothing happened.

In 1981 the International Law Commission began the work that would end with the 1998 International Criminal Court by drafting the Code of Crimes Against the Peace and Security of Mankind.  This work was spurred on by the UN Security Council's establishment of two ad hoc war crimes tribunals for the former Yugoslavia in 1993 and for Rwanda in 1994.

The Yugoslavian tribunal has jurisdiction in cases of grave breaches of the Geneva Convention of 1949, but the tribunal appeals chamber ruled that the concept must be assumed to be restricted to cases of armed conflict between states, and thus, for instance, could not be used in case of non-interstate aspects of the Yugoslavian Civil War.  They did, however, allow for “a change in customary law concerning the scope of the ‘grave breaches’ system might gradually materialize.”  The tribunals also have the authority to prosecute individuals violating the laws of war with regard to all, serious violations of humanitarian law.  Finally, and most significantly, the appeals chamber overruled the old principles of the Nuremberg Trials that to prosecute individuals suspected of crimes against humanity, there had to be aspects of either war crimes or crimes against peace.  It concluded that “customary international law may not require a connection between crimes against humanity and any conflict at all.”  This is an all the more conspicuous ruling because it disagrees with the tribunal's own statutes which explicitly restricts the tribunal only to deal with crimes against humanity related to armed conflict.

In the case of the Rwandan war crimes tribunal, which dealt with a completely intra-national civil war, most of the Geneva Convention of 1949 is inapplicable—as it deals with interstate wars—but a part that is applicable is article 3:

“In the case of armed conflict not of an international character occurring in the territory…each Party to the conflict shall be bound to apply, as a minimum, the following provisions: …Persons taking no active part in the hostilities…shall in all circumstances be treated humanely, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria.  To this end the following acts are and shall remain prohibited at any time and in any place whatsoever with respect to the above-mentioned persons:  (a) violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture; (b) taking of hostages; (c) outrages upon personal dignity, in particular, humiliating and degrading treatment; (d) the passing of sentences and the carrying out of executions without previous judgment pronounced by a regularly constituted court affording all the judicial guarantees which are recognized as indispensable by civilized peoples.”

Further jurisdiction in cases of crimes against humanity and genocide is granted the tribunal by their treaty itself.

The final landmark in the development of international war crimes tribunals so far is the formation of the permanent International Criminal Court which entered into force in 2002.  The statutes define its role as follows:

“The jurisdiction of the Court shall be limited to the most serious crimes of concern to the international community as a whole.  The Court has jurisdiction in accordance with this Statute with respect to the following crimes: (a) The crime of genocide; (b) Crimes against humanity; (c) War crimes; (d) The crime of aggression.”

It is unclear at the moment what exactly a crime of aggression constitutes, and until a definition is made, crimes of aggression are not under the jurisdiction of the ICC.  They have taken cues from the two ad hoc tribunals in that when dealing with interstate wars they have jurisdiction in cases of grave breaches to the Geneva Convention and other serious violations, and when dealing with intrastate wars they have jurisdiction in cases of serious violations of article 3.  They do not have jurisdiction in cases of crimes dating before the formation of the court, but the list of crimes under the jurisdiction of the court can be amended.

A noteworthy addition to humanitary law is the fact, that it allows for the relief of criminal responsibility for crimes committed under orders of a superior.  This is only under certain circumstances—a legal obligation to obey orders, ignorance of the unlawfulness of the order, and the order was not manifestly unlawful (as an order to commit genocide would most certainly be)—but this is still a breach of customary law.  Usually, under no circumstances would orders act exculpatory, and, indeed, so far it hasn't in any of the tribunals, although it might count as a mitigating circumstance.

The historical importance of the ICC on international and humanitarian law—both customary and positive—is yet to be seen.  The court enjoys almost worldwide recognition, but it has yet to condemn anybody, and scepticism abounds that it will be unanble to excercise its jurisdiction in cases dealing with miliarily strong contracting parties; the fear that only the defeated will be tried, never the victors.  Also, much have been said about the absence of American recognition, but this does not necessarily make nor break the institution.  Rome wasn't built in a day.

Further reading:

  • Rome Statute of the International Criminal Court:
  • Draft Code of Crimes Against the Peace and Security of Mankind:
  • Agreement for the Prosecution and Punishment of the Major War Criminals of the European Axis, and Charter of the International Military Tribunal:
  • Kellogg-Briand Pact:
  • Resolution 95(I) Affirmation of the Principles of International Law recognized by the Charter of the Nürnberg Tribunal:
  • Geneva Convention of 1949 (I–IV):
(This is part of my personal quest (study) on international and humanitarian law)