The Evolution of International Criminal Law

A Bird's-Eye View of the Past Century

Every human society, if it is to live in security and freedom, must be governed by a system of clear laws, courts with binding authority and effective enforcement of generally accepted norms. Yet, international "laws" are often ambiguous or non-existent, courts to settle international disputes have only limited authority and enforcement is almost completely lacking. The creation of a permanent International Criminal Court to punish perpetrators of the worst crimes against humankind is still in its formative stages with details now being debated at the United Nations. Small wonder that there are millions of people throughout the world who continue to live in constant fear and misery. Here we shall trace the outlines of a century of slow evolutionary progress as hesitant nations reach out cautiously for a more civilized and humane planetary society. Seeing history in its proper perspective should encourage hope that, as we enter the next millennium, the future will be brighter than the past.

From The Hague to Nuremberg

International law is a fairly recent creation. In biblical times, unrestrained killing of your enemy, as well as his suckling babes, was a common practice; taking captives as slaves was a humanitarian advance. Roman law and church doctrines outlined principles for "just wars" and violators were subject to banishment, excommunication, torture or worse. Medieval sovereigns were presumed to reign by Divine right and thus immune from man-made law. When treaties were breached, the ultimate remedy was to resort to war.

From the 16th to the 18th centuries, scholars such as Puffendorf at Heidelberg and Grotius in Holland, advocated new approaches to govern international society. The English philosopher Jeremy Bentham is credited with having used the term "international law" for the first time around 1789. In 1795, Immanuel Kant's Zum ewigen Frieden - inspired by the revolutions in France and America - advocated an international order requiring all states to be bound by ethical and legal rules. During the unrestrained American civil war in the 1860's, President Abraham Lincoln called upon Professor Franz Lieber (a former Prussian officer who was teaching at Columbia University in New York,) to draft a set of humanitarian rules to govern the behavior of soldiers in the field. Detailed reforms of the international legal system were advocated by such scholars as Professor Johann Kaspar Bluntschli of Heidelberg who wrote Das moderne Volkerrecht der Civilisierten Staaten, als Rechtsbuch dargestelt (1868). But plans for a reformed world order were scoffed at by military heroes like Prussian Field-Marshal von Moltke; militant decision-makers went about their business of killing as usual.

It was in 1899, only a century ago, that what was heralded as "The First International Peace Conference" was convened. The title was a misnomer. In fact, it was a disarmament conference initiated by the Czar of Russia who found himself in a financially unbearable arms race with France. Delegates from 26 self-styled "civilized states" came together for about 10 weeks in pleasant surroundings at The Hague where they filled the summer air with flowery speeches. Compulsory arbitration of disputes was rejected; instead they focused on more humane ways of slaughtering each other. At the end, they drew up three Conventions, three Declarations and six Voeux or wishes, carefully laced with ambiguities and exceptions. Signatories agreed to "use their best efforts"... "as far as possible" and to disregard the rules if national honor or "essential interests" might be endangered. It was more a wish list than a binding accord. The problem of enforcement was not even mentioned.

A follow-up Second Hague Conference, expanded to 50 participants, took place in 1907. It improved some of the earlier texts but was not significantly different. In truth, leading participants were not ready to accept major changes in the legal order. The melancholy conclusion is confirmed in a private letter from the German Kaiser Wilhelm II in 1906. The Monarch made plain that he would reluctantly attend the Hague Conference but in practice he would continue to rely only on his "God and sharp sword". His contempt for rules of war or law was confirmed by his defiant boast, in rather pungent barroom language, that he would disregard all the resolutions. [1] It would not be long before nations found themselves in the midst of the unparalleled tragedy that became known as The First World War.

After some 10 million soldiers and another 10 million civilians had been killed and another 20 million dead from famine and disease, there was an enormous public outcry among the victims that those responsible for the war, and for such atrocities as using poison gas and sinking hospital ships in violation of the Hague Conventions and customs of war, should be held to criminal account. In November 1918, with the war lost, Kaiser Wilhelm II abdicated and fled to Holland; which had remained neutral.. A Peace Conference of the "Great Powers" in 1919 led to the appointment of a committee of legal experts to determine the "Responsibility of the Author's of the War." Germany was found to be the principle culprit. Since, at that time, there was no international court competent to try a sovereign Head of State and no one had ever been convicted for the crime of aggression before, the Dutch refused to extradite Wilhelm and he lived famously as "the woodchopper of Doorn."

The frustrated Committee of Experts recommended that it should be made clear that—in the future—aggression would be punished as an international crime. Unable to indict the German Monarch for aggression against "little Belgium," a face-saving provision was written into the Treaty of Versailles requiring Germany to hand the Kaiser over to stand trial for " a supreme offense against international morality and the sanctity of treaties". In addition, about 900 listed German officers accused of atrocities were to be surrendered for trial by an Allied war crimes court. Although Germany had signed the Treaty, these provisions were denounced as a diktat and Germany refused to comply. After much wrangling, it was finally agreed that the Germans would try their accused in their own Supreme Court at Leipzig. The Kaiser was never put on trial and, as might have been expected, almost all other defendants were acquitted; those few who were convicted received light sentences or soon managed to escape.

American President Woodrow Wilson campaigned vigorously, for the creation of a League of Nations as part of the Versailles Treaty. But, the U.S. Constitution required consent by two-thirds of the Senate before any treaty could be ratified. A small number of conservative Senators succeeded in blocking ratification and thus the League's strongest advocate never became a member of the first international organization created to maintain peace. The Covenant of the League envisaged the use of economic sanctions—"the economic weapon"—to deter war. But enforcement required consent of all the Members; everyone had a veto right. It soon became clear that nations were still not ready to yield their sovereign prerogatives. Just as they had failed to accept adjudication or arbitration of disputes when those subjects were debated at the Hague in 1899 and 1907, they remained unwilling to give up their right to go to war and to decide for themselves when sanctions against aggressors should be applied.

Japan invaded Manchuria in 1931 and Italy brazenly attacked Ethiopia in 1935 in clear violation of the League's Covenant. The League failed to take collective economic or military measures to halt the aggression. The United States Congress, influenced by its isolationist members, passed laws to assure American neutrality. Hitler, defying the Peace Treaty, marched his troops into the Rhineland in 1936. Japan launched another aggression against China in 1937. The next year, Germany annexed Austria and moved against Czechoslovakia. World political leaders, longing for peace and fearing war, still failed to take decisive collective action to stop Hitler's march of conquest. The peace plan of the League was never given a chance. Instead, nations began, as they had in the past, to scramble for new military alliances that might save them. On September 1, 1939, German planes launched a massive Blitzkrieg against Poland; its allies France and the United Kingdom reluctantly declared that they were at war with Germany. The world was soon engulfed in World War II.

The Nuremberg Trials

There is no need to recount here the aggressions, crimes against humanity, war crimes and other atrocities committed during the dozen-year reign of Adolf Hitler's "Thousand- Year Reich." Long before the war ended, Germany had repeatedly been warned by the Allied Powers that those responsible for causing the war and the crimes against humanity that - were being committed on a massive scale would have to answer for their deeds. In May 1945, Germany surrendered unconditionally. The British proposal - that arch-criminals should simply be taken out and shot - was opposed by the United States that insisted upon fair trials for the accused. It took the four occupying Powers

(US, UK, France and USSR) a scant six weeks to reach agreement in London on a Charter that set down the law and procedure that would govern the proceedings of the International Military Tribunal (IMT) created to conduct war crimes trials at Nuremberg. The opening statement by America's Chief Prosecutor, Robert M. Jackson (a Judge on leave from the US Supreme Court) gave assurance that the primary purpose was to advance law and justice:

That four great nations, flushed with victory, and stung with injury stay the hand of vengeance and voluntarily submit their captive enemies to the judgment of the law is one of the most significant tributes that Power has ever paid to Reason ... To pass these defendants a poisoned chalice is to put it to our own lips as well. We must summon such detachment and intellectual integrity that this trial will commend itself to posterity as fulfilling humanity's aspirations to do justice. [2]

The IMT Charter gave the Tribunal jurisdiction over only three categories of crimes: (a) Crimes against Peace, which meant the preparation and waging of a war of aggression, (b) War Crimes, namely violations of the traditional laws and customs of war, and (c) Crimes against Humanity, such as extermination and enslavement of civilian populations. Leaders who conspired to commit those crimes would be culpable, regardless of rank or station and superior orders would be no excuse.

Twelve subsequent war crimes trials, based on a slightly improved Charter (Control Council Law No. 10) were then held at Nuremberg under the direction of General Telford Taylor (later Columbia University Professor). The entire panorama of Nazi domination and crime was exposed and the record of incredible criminality was unquestionably confirmed by official German documents. Responsible leaders from various spheres - doctors, lawyers, ministers, industrialists, militarists and SS killers - were called to account in courts established by the United States. Similar trials of Japanese war criminals took place in Tokyo and in countries that had been occupied by the Axis powers. These trials further reinforced the principles of law laid down by the IMT. The Nazi defendants at Nuremberg, represented in open court by lawyers of their own choice and confronted by their own undeniable records, were given fair trials the likes of which they— in the days of their own pomp and power—never gave to anyone.

Contrary to popular belief, the Nuremberg Charter was not something that was suddenly invented from whole cloth. The long list of precedents cited by the distinguished IMT jurists made plain that the Charter was not ex post facto justice. Its articulation of Crimes Against Humanity reflected and clarified emerging precepts expressed in the Conventions at The Hague and other international pacts where nations, groping, for a more humane order, relied on "the laws of humanity and the dictates of the public conscience." Nuremberg confirmed that when cruelties, such as genocide, reached a magnitude that shocked the conscience of humankind, it should and could be punished as a crime against all of humankind.

In charging defendants with the crime of aggression, Nuremberg admittedly took another small step forward that deliberately went beyond the sterile legalisms developed during the age of imperialism. The IMT judges noted that the law is not static and must grow to meet the needs of a changing society. Justice Jackson said it best: "It is high time that we act on the juridical principles that aggressive war- making is illegal and criminal ... so as to make war less attractive to those who have governments and the destinies of people in their power." [3]

Nuremberg's greatest contribution was that it sought to eliminate the source of the most devastating human rights violations: war-making itself. For the first time in human history, aggressive war was repudiated as a national right and condemned as an international crime. The Nuremberg and subsequent war crimes trials were the foundation stones on which a new order of humanity, international justice and peace were to be built.

The United Nations Moves From Stalemate to Action

Nineteen other nations adhered to the Nuremberg Charter. The Nuremberg Principles and Judgment were unanimously affirmed by the entire General Assembly of the United Nations in 1945. Outraged by the Nazi inhumanities revealed by the Nuremberg trials, the United Nations promptly appointed committees to codify the Nuremberg Principles into a criminal code and to create an international criminal jurisdiction where such offenses, including the crime of genocide, could be punished and deterred. Unfortunately, the advent of the "cold-war" paralyzed effective action at the UN where, for many years, the efforts at codification and implementation of international criminal law were stymied. UN committees drafted Statutes in 1951 and 1953 for an International Criminal Court. In 1954 a draft Code of Offenses Against the Peace and Security of Mankind was debated but no consensus could be reached on either Code or Court. One of the excuses given to justify the lack of progress was that without a precise definition of the crime of aggression there could be no complete criminal Code; without such a Code there was no need for a Court. While diplomats quibbled, aggressive wars and massive crimes against humanity continued to be committed throughout the world.

The Nuremberg court in condemning aggression as "the supreme international crime" - even without a precise definition - reasoned that decisions to go to war are made by individuals and not by abstract entities. Key Nazi leaders must have known that what they were doing was a violation of international law. Justice demanded that the persons responsible for the war must be held to account in a court of law. After years of meticulous debate, the UN, without a vote, adopted a consensus definition of aggression in 1974. All agreed that "a war of aggression is a crime against international peace." The UN Charter made clear that it was the duty of the Security Council to determine the existence of an act of aggression. The consensus confirmed that the Council could decide whether aggression had occurred "in the light of all the circumstances." Despite vague formulations, that were accepted in order to reach consensus, the existence of the definition cleared the path for further progress on the criminal Code and Statute for the proposed new International Criminal Court.

While the International Law Commission, a body of 34 "independent" legal experts, continued its plodding efforts to reach agreement on a draft international criminal Code and the Statutes for a criminal court to enforce the Code, armed conflict erupted in the former Yugoslavia. Rival ethnic, religious and political groups attacked each other with uncontrolled ferocity. Worldwide television showed prison camps reminiscent of Dachau and Auschwitz. Confirmed reports described how thousands of women had been raped and many more thousands of innocent civilians were brutally driven from their homes in what was euphemistically called "ethnic cleansing." There was nothing clean about it; it was filthy genocide! An outraged public demanded action to bring the criminals to account. The UN Security Council, acting within its Charter authorization to create subsidiary organs, promptly created an ad hoc International Criminal Tribunal (ICTY) to try those who had committed crimes against humanity in the former Yugoslavia since 1991.

In 1994, a brutal civil war erupted in Rwanda. An Investigative Commission appointed by the UN Security Council confirmed that perhaps half-a- million men, women and children had been systematically and savagely hacked or bludgeoned to death by rival ethnic tribes in that devastated country. Powerful nations, reluctant to interfere in an internal conflict that did not threaten their own vital interests, failed to intervene in time to halt the genocide. Again responding to public outrage, the Security Council quickly created another ad hoc criminal court (ICTR) authorized to bring to justice those leaders who were responsible for the genocide and other crimes against humanity committed in Rwanda in 1994. To save money, the ICTR, located in Tanzania, was administratively linked to the ICTY that was headquartered in The Hague. What is particularly noteworthy is that, once the political will was aroused, it was possible for the Security Council - in a matter of months -to lay foundations for new criminal courts authorized to bring before the bar of international justice those accused of major 'crimes against humanity. The Council had invented International Criminal Courts a la carte!

It was to be expected that these new legal institutions, lacking their own financial resources and enforcement personnel, would encounter enormous legal, political and administrative problems. Several high-ranking indicted suspects, for example, still remain at large in former Yugoslavia and elsewhere. Powerful nations hesitate to take the risks involved with forcible arrests and the Security Council often fails to provide necessary support to its own legal offspring. What is remarkable is that - despite the many difficulties - the ad hoc tribunals have managed to function as well as they have. It is a tribute to their dedicated prosecutors, judges and staffs that they have already established a record of fair trials against a number of significant wrongdoers. The tribunals have also set important precedents for the further development of international criminal law and procedures. They have, to a certain extent, helped to diffuse animosities by encouraging peace through justice rather than vengeance. The ad hoc tribunals created by the Security Council are new born babes on the international scene; they must be helped to grow as additional stepping stones toward a more humane world order under law.

A Permanent International Criminal Court

A string of temporary tribunals, created after enormous crimes have been committed and with jurisdiction limited in time and place, is certainly better than allowing vengeance to run rampant or granting effective immunity to mass murderers. But temporary courts created a la carte on a selective basis are not good enough. To be respected, international law must apply equally to everyone, everywhere. Human rights must apply equally to all humans. The continuing existence of massive crimes against humanity cried out for the creation of a permanent International Criminal Court (ICC) to bring to account those who threaten the peace and security of human beings anywhere; regardless of ethnicity, color, religious or political persuasion. It seemed to many that the time had come to close a glaring gap in the international legal order.

The UN General Assembly prodded the International Law Commission to accelerate its work. In 1994, the Assembly created a Preparatory Committee to take the lead in creating the ICC. By 1998, the Committee had made great progress but the differences still remained formidable among nations with different legal and social traditions. Small states, distrustful of courts created by a Security Council that many viewed as politically biased, favored a completely independent tribunal. Some powerful states, while professing, support for a more effective legal mechanism, seemed quite content with the existing legal order based on military might. The hundreds of legal, procedural and technical difficulties that had to be overcome before compromises could be acceptable to hundreds of sovereign nations imposed' enormous challenges.

The climax to a century of hope and years of preparation was reached in Rome on 17 July 1998. Following five weeks of intensive negotiation, high-ranking representatives of major world powers, by a vote of 120 in favor and only 7 against, reached agreement on a draft Treaty the opening sentence of which proclaimed: "An International Criminal Court is hereby established." Chairman Philippe Kirsch of Canada quivered with emotion as he hailed the historical moment. UN Secretary-General Kofi Annan flew to Rome to celebrate what he called "a gift of hope to future generations, and a giant step forward in the march toward universal human rights and the rule of law." [4]

The understandable euphoria obscured the fact that many compromises that were necessary to reach the successful conclusion significantly diluted the original aspirations. Many important nations, including the United States, China and India, did not seem to share the wild enthusiasm. Furthermore, the Court could not start functioning until at least 60 nations ratified the Treaty ; that might require difficult constitutional amendments. There were severe limitations on the Court's jurisdiction: The International Court could act only in those cases where national states were unwilling or unable to grant the accused a fair trial; the Prosecutor could not act without prior approval by judicial supervisors. In certain cases, the defendant could not be indicted unless the state of his nationality consented to the trial. A host of procedural rules would still have to be agreed upon before the Court could begin to operate and there was no agreement on how the tribunal was to be funded. A new Preparatory Commission went to work promptly in an effort to complete the vital unfinished business during the year 2000.

From a historical perspective, one of the major disappointments was the inability of states to accept the Nuremberg conclusions regarding the crime of aggression. Some States seemed not to recognize that the General Assembly mandate in 1945 required that the Nuremberg crimes-of which aggression was the heart-should be incorporated into a criminal code for prosecution by an International Criminal Court. Others, had not participated in the intensive debates that had produced the consensus definition of aggression in 1974, argued that aggression was still inadequately defined for purposes of a criminal statute. These differences were intensified by distrust of the Security Council and its unfair veto power. There just was not enough time in the hectic days at Rome to reach an accord. In the face of serious danger that the greatest of all crimes would be dropped from ICC's jurisdiction altogether, it was rescued by a last-minute procedural compromise: the Court could take no action on aggression until nations agreed on its definition and the role of the Security Council. Furthermore, expanding ICC's jurisdiction to deal with the crime of aggression could only be considered as an amendment to the Rome Statute that could be taken up seven years after the Treaty had been ratified by 60 nations - whenever that might be. Estimates vary about when the International Criminal Court will become a functioning reality; optimists say it may be only a few more years.


The events we have sketched did not take place in a vacuum. The world is in incessant turmoil and one century is barely a blink in the eye of time. Yet, in the field of our particular focus, certain patterns slowly emerge from the turbulent and murky darkness. We described how powerful sovereigns began the century by striving to ameliorate the intolerable burden of an arms race. Their efforts, cloaked in a longing for peace, were too feeble to overcome ancient traditions. National leaders who controlled the destiny of people in their domain sought security and freedom for themselves and their people through war rather than law. Their inability to devise or accept new rules to govern the conduct of independent states cost the lives of millions of innocent subjects who died a miserable and violent death as pawns in futile struggles for national power or prestige.

From the ashes of despair of the Second World War arose a renewed determination of people everywhere to seek a more tolerable structure of international society. The United Nations was created primarily "to save succeeding generations from the scourge of war". A Universal Declaration of Human Rights was widely acclaimed. The judgments at Nuremberg declared that aggression, crimes against humanity and grave breaches of the rules of war would no longer go unpunished. No one then anticipated that these pillars of peace were being built on sand. Subsequent tragedies demonstrated that many countries could not escape their past habits of violent thought and action. Nothing had been able to eliminate the age-old rivalries between those who had faith in law and those who had faith only in war. Amidst the continuing chaos, slow progress toward a rule of law and the protection of fundamental freedoms can be discerned by the eager and perceptive eye.

Over the years, new methods were found to expand the reach of international justice. New regional courts were created, in Strasbourg and elsewhere, where aggrieved individuals could bring even their own governments to account for human rights violations. An international Law of the Sea Tribunal was erected in Hamburg to settle maritime disputes by peaceful means. There arose a growing willingness to settle commercial differences without resource to force. Even the International Court of Justice, with its limited jurisdiction to deal only with disputes among consenting states, was busier than ever with Decisions and Advisory Opinion covering interpretations ranging from the Genocide Convention to the lawfulness of nuclear weapons.

International criminal law is clearly on the march. The tribunals created by the Security Council to vindicate barbarities committed in Yugoslavia and Rwanda are now fully functional. A permanent International Criminal Court - despite pre-natal shortcomings - is in formation. Instantaneous communications now alert the world to outrageous atrocities wherever they occur. International Criminal Courts are being considered to penalize crimes against humanity committed in Cambodia, Iraq, Sierre Leone and many other lands. Chile's former Dictator Augusto Pinochet, despite a self-granted writ of immunity, remains confined in England to answer an arrest warrant issued by a Spanish court charging him and his cohorts with systematic torture of Spanish citizens. Non-governmental organizations, that played a very significant role in advancing the International Criminal Court, have become vigorous proponents of fundamental human rights everywhere. This past century marks the spread of democracy and with it the inevitable erosion of state power; the individual citizen comes under the protective mantle of international jurisprudence.

Albert Einstein warned that to avoid the drift toward endless catastrophe we must adopt new ways of thinking. "What is at stake," he said, "is the life or death of humanity." To be sure, there has been significant progress toward security and peace but much new thinking is still needed. Nuclear weaponry poses a universal threat. Internal conflicts continue to stain the human landscape with uncontrolled violence. International law does not require the world community to tolerate the intolerable, the parameters of the right to self-determination and the means that may legitimately be employed to achieve that worthy goal must also be clarified and enforced. Lawful goals cannot be sought by unlawful means. Tolerance and compassion must be taught to replace the blind hatred that animates human brutality. An impartial international judiciary authorized to deal with disputes that threaten human existence is a vital tool for a peaceful world.

The United Nations, and particularly the Security Council, must be reformed if it is to fulfill its promise to humanity. There must be clearer rules about when unilateral or multilateral intervention without Security Council mandate may be permissible. No one, and no nation, should be entitled to take the law into its own hands. Aggression can not be disguised as humanitarianism. We now live in a global society where all major problems are global and can only be solved globally. No person and no nation can feel secure until all are secure. If one reviews the positive trend of history - despite delays and shortcomings - one can find the hope and the energy needed to move toward a more humane and peaceful future.

Benjamin B. Ferencz, J.D., Harvard, 1943, was Chief Prosecutor in the Einsatzgruppen Trial at Nuremberg and directed the post-war programs seeking restitution for Nazi victims.

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[1] "Ich scheisse auf die ganzen Beschluesse!" See Jost Dulffer (Duelffer), doctoral dissertation: Regeln gegen den Krieg? Die Haager Friedenskonferenzen 1899 und 1907 in der internationalen Politik; Berlin Ulstein (1981) p. 93. I am indebted to Prof. Klaus Schlichtmann for drawing my attention to this citation.

[2] Robert H. Jackson, The Case Against the Nazi War Criminals (N.Y. Knopf, 1946) pp. 3-7.

[3] Mr. Justice Jackson's Report to the President, June 6, 1945, International Conference on Military Trials (London, 1945) pp. 42-54.

[4] UN Press Release L/ROM/23, 18 July 1998.