“A crime is any act or omission prohibited by public law for the protection of the public, and made punishable by the state in a judicial proceeding in its own name. It is a public wrong, as distinguished from a mere private wrong or civil injury to an individual” (Clark & Marshall  1952, p. 1). This is an authoritative definition of crime as a concept in municipal law. In any municipal law system, even a very primitive one, there is a substantial body of criminal law wherein are defined many crimes, and provision is made for legal machinery to try and to punish criminals.
Although international law in the modern sense has been in existence for over three hundred years, the states of the world have not developed a very extensive body of international criminal law. Very few crimes are defined by positive international law, and there is no permanent legal machinery for the trial of persons accused of international crimes. Still, the concept of international criminal law has been firmly established. In order to discuss the specific details of that law let us first indicate the place of international criminal law in general international law.
International law is that law which states and other international entities (e.g., international organizations, nonsovereign parties to international conflicts) create to govern their mutual relations. It is a body of law made, interpreted, enforced, and changed by its subjects rather than by a higher authority. Accordingly, the definition of international crimes and the application of sanctions against transgressors result from the interaction of states in this decentralized law-making process. No theoretical criminal code or judicial machinery which does not receive the acceptance of a working majority of states is in any sense binding international law.
International crimes must be distinguished from international delicts generally. As a corollary of their rights as sovereigns, states bear responsibility for their own acts and for acts committed within their jurisdiction which violate international law and are injurious to the rights of other states and their nationals. That this responsibility is a corporate responsibility of the state qua state was the position taken in the traditional doctrine. International crimes are those international delicts for which individuals, as distinct from states, are directly responsible under international law.
International crimes must also be distinguished from international torts. Crimes are illegal transgressions against the rights of the public, or the common good, and the criminal must be punished in the name of the public; torts, on the other hand, are violations of private rights for which the law provides a remedy. There are a great many international torts, or “denials of justice,” recognized by international law. Injured individuals seek remedies for such torts through the diplomatic intercession of the state to which they owe allegiance, notably through international reclamations. But an international crime is a transgression against the whole international legal order and must be punished on behalf of that order. One important result of this distinction is that whereas remedies for international torts may be sought only by a state having personal jurisdiction over the claimant (or, as in the UN Reparations Case, by an international organization for its own personnel), any and all states have a right and duty to apprehend, try, and punish international criminals.
Finally, the punishment of international criminals must be distinguished from other sanctions of international law. It is notorious that international law is comparatively lacking in sanctions. Traditionally the principal sanction was self-help, coercion exercised both to uphold a state’s rights and to deter and punish unlawful behavior. Under the right of self-help, measures that would ordinarily be illegal were justified by the need to oppose antecedent delictual conduct, either by repelling it (self-defense) or deterring and punishing it (reprisals). The right of self-help with armed force is much reduced in the modern regime with respect to recourse to force, jus ad bellum, and it is questionable whether armed reprisals are permissible. But in the law governing hostilities, jus in bello, reprisals are still permitted and they are generally considered to be the principal sanction for the law of war. International criminal law as a sanction seeks to punish the specific individuals who are guilty rather than, as is the case in most recourse to self-help, persons who only have the same nationality as the perpetrators of international delinquencies. This distinction would also be of importance in cases of enforcement of the law by the United Nations or other international organizations.
The history of international criminal law is the history of the evolution of the status of the individual in international law. The classical doctrine held that only states were “subjects” of international law, that only they were international persons possessing rights and duties directly under the law. Individuals were deemed to be “objects” of international law, which reached them only through the intermediary of states. Until individuals were recognized as possessing a degree of international personality, responsibility for their internationally delictual conduct could be attributed only to the state to which they owed allegiance. This view predominated with few exceptions until after World War I.
The best known international crime in earlier times was piracy. In 1820, for example, Justice Story asserted:
The common law, too, recognizes and punishes piracy as an offense, not against its own municipal code, but as an offense against the law of nations (which is part of the common law), as an offense against the universal law of society, a pirate being deemed an enemy of the human race…. The general practice of all nations in punishing all persons, whether natives or foreigners, who have committed this offense against any persons whatsoever, with whom they are in amity, is a conclusive proof that the offence is supposed to depend, not upon the particular provisions of any municipal code, but upon the law of nations, both for its definition and punishment. (United States v. Smith 5 Wheaton 153 in Bishop  1962, p. 266)
Thus all states had jurisdiction over pirates for the reason that such persons had committed an offense against international law. Piracy has recently been defined in the 1958 Geneva Convention on the High Seas, and it remains an international crime. According to the convention, piracy consists of any of the following acts:
(1) Any illegal acts of violence, detention or any act of depredation committed for private ends by the crew or the passengers of a private ship or a private aircraft, and directed:
(a) On the high seas, against another ship or aircraft, or against persons or property on board such ship or aircraft;
(b) Against a ship, aircraft, persons or property in a place outside the jurisdiction of any state;
(2)Any act of voluntary participation in the operation of a ship or of an aircraft with knowledge of the facts making it a pirate ship or aircraft;
(3)Any act of inciting or of intentionally facilitating an act described in subparagraph (1) or subparagraph (2) of this article. (Bishop  1962, p. 466.)
The recognition of other international crimes in the pre-World War I period was not so clear-cut and emphatic. In the late eighteenth and nineteenth centuries, the slave trade was increasingly recognized as immoral and was prohibited by municipal law in many states; gradually, in a number of international agreements, it became recognized as an international crime punishable by any state. Violation of diplomatic immunity was held to be an international crime, although punishment for such violations was usually accomplished through the municipal courts of the state in which they occurred. Counterfeiting of foreign moneys or securities was considered a crime which a state must punish. Finally, individual responsibility for violations of the law of war was well established by the eighteenth century.
Three major developments after World War I greatly increased prospects for international criminal law. First, the Versailles Treaty introduced the concept of individual responsibility for war crimes and for what would today be called crimes against the peace. Even though the German kaiser escaped trial and justice was not done in the trials in municipal German courts of accused war criminals, the concept of war crimes was strengthened and broadened. Second, the German-Polish Convention relating to Upper Silesia gave major impetus to a trend toward attributing international law rights and duties directly to individuals (although the system thereby created was not in itself concerned with international crimes). Third, the League of Nations system gave birth to functional organizations which defined as international crimes engaging in white slavery, illegal narcotic and drug trade, and customs violations. In addition to these developments, the interwar period saw a marked increase in research and writing about international criminal law. One major aspect of this literature was its concern for the suppression of political terrorism which affronted the whole international legal order, such as the assassination of notables in Marseilles in 1934.
Of course, the tragic events of World War II produced a major breakthrough in this field. From the many war crimes trials, national as well as international, came an enormous body of case law. In the wake of these trials and a vast accompanying body of national executive decrees and legislation, the international law-making process produced conventions such as the Genocide Convention, the Human Rights Convention, the Geneva Conventions of 1949 and 1958, all of which contain provisions relevant to a growing but still fledgling international criminal law.
Virtually all of the war crimes trials after World War ii have been based on the precedent set by the International Military Tribunal in its judgment of October 1, 1946. The jurisdiction of the tribunal was established by the London Agreement of August 8, 1945, and the charter annexed to that agreement. Authority for the agreement, in turn, was based upon the right of debellatra, that is, the right of the victorious Allies to deal with the defeated Axis powers. References to war crimes trials as “victor’s justice” generally connote opprobrium, but it should be emphasized that in the absence of a higher international authority, it is, generally speaking, only when there is a victor that there can be a war crimes trial.
The indictment brought against Hermann Göring and other Nazi leaders included four counts. The first charged participation of all the accused in “a common plan or conspiracy” to commit the crimes covered by the remaining counts. Count two, “crimes against peace,” charged them with having “participated in the planning, preparation, initiation and waging of wars of aggression, which were also wars in violation of international treaties, agreements and assurances….” Count three, “war crimes,” charged them with war crimes as defined in the charter, i.e., numerous violations of the law of war. Count four, “crimes against humanity,” charged them with “violations of international conventions, of internal penal laws and of the general principles of criminal law as derived from the criminal law of all civilized nations….” All but three of the accused who lived through the trial were found guilty on enough counts (usually all) to warrant the death sentence, with the exception of Rudolf Hess, who received life imprisonment (International Military Tribunal 1947-1949, vol. 1, “Indictment,” pp. 27 ff., “Judgment,” pp. 171 ff.).
It is fair to say that the evidence of the acts with which the accused were charged was overwhelming. If what the accused had done engendered individual criminal responsibility under international law, they were clearly criminals. But the defense objected, first, on the grounds that only states were responsible for alleged international delictual behavior and that individuals acting for a sovereign state are immune from international legal prosecution. In a ruling which goes to the heart of international criminal law, the judgment of the court found that “crimes against international law are committed by men, not by abstract entities, and only by punishing individuals who commit such crimes can the provisions of international law be enforced” (International Military Tribunal 1947-1949, vol. 1, p. 223). In this connection the court followed the provisions of the London Charter, which precluded the plea of superior orders as a bar to prosecution but admitted it as a justification to be considered “in mitigation of punishment” (International Military Tribunal 1947-1949, vol. 1, p. 223).
The second fundamental objection of the defense was that the acts set forth in the indictment were not crimes when performed and that the charges constituted ex post facto laws violative of the principle “Nullum crimen sine lege, nulla poena sine lege.” Aside from the opinion of the court that this principle is not absolute, it was held that all transgressions mentioned in all of the counts were in fact recognized as crimes under positive international law at all relevant times. Although the court did not so distinguish the counts, it is necessary to analyze each one somewhat differently, insofar as the contention that they were known to be crimes by the accused is concerned (International Military Tribunal 1947-1949, vol. 1, p. 219).
It is apparent in retrospect that the count of conspiracy was primarily the work of the Englishmen and Americans participating in the trial and that it may have been overstressed. It probably does not materially alter the interpretations of the other counts except to underscore the deliberate character of the criminal acts done. The validity of count two, “crimes against peace,” depends upon the contention that after 1918, when recourse to force was neither legal nor illegal but a legally neuter prerogative of all sovereign states, the international legal order developed a prescription against aggressive recourse to force. On the basis of the total fabric of international agreements directed to this end, the court found that such a prescription had been established and was well known to the accused. Count three, “war crimes,” is unexceptional. As we have said, the right to punish such crimes had been recognized for a century and a half or more. Finally, count four, “crimes against humanity,” is in turn somewhat different, since it really is based on the higher law concept that some things are recognized as crimes by all men and all legal systems. Failure to specify these crimes in positive international law does not prevent justified punishment for their commission.
There were many criticisms of the Nurembergtrials of major war criminals, their counterparts the Tokyo trials, and hundreds of lesser trials held by other war crimes tribunals as well as by regularly constituted municipal courts (see the excellent series by the UN War Crimes Commission 1947-1949, which has a summary in vol. 15). But the lasting contribution of these trials to international criminal law will depend upon the acceptance, rejection, or alteration of the principles they established. In this regard, the postwar period has seen a mixture of favorable, unfavorable, and innocuous developments. On the positive side we may cite:
(1)The reaffirmation by the UN General Assembly of the principles of Nuremberg by a resolution of November 21, 1947, and, at the request of the Assembly, the preparation by the UN International Law Commission of a Draft Code of Offenses Against the Peace and Security of Mankind in 1954 based largely on the Nuremberg Judgment.
(2)The adoption by the General Assembly on December 9, 1948, of the Convention on Genocide, which entered into force January 12, 1951 (see below).
(3)The adoption by a conference in Geneva on August 12, 1949, and subsequent ratification by many states of the Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field, of the Convention for Amelioration of the Conditions of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea, and of the Convention Relative to the Treatment of Prisoners of War, all of which prohibit a number of the practices covered in counts three and four at Nuremberg, particularly in a common article III setting minimal standards of conduct, even for conflicts not of an international character.
(4)Continuation by the government of the German Federal Republic of municipal war crimes proceedings against persons within its jurisdiction.
(5)The trial and execution of Adolf Eichmann for his participation in the crime of genocide against Jews and others during World War II on the basis not of a victorious belligerent or a state having territorial jurisdiction, but of universal jurisdiction, as well as of the character of the crimes in question and their specific character as being designed to exterminate the Jewish people. Although the irregular recovery of Eichmann from Argentina by Israeli agents and some aspects of the trial have been criticized, it nevertheless constitutes an important precedent for international criminal law.
On the negative or inconclusive side we may list the following developments:
(1) Abandonment of indictments prepared for war crimes trials in the Korean War, because the absence of a “victor,” the presence of large numbers of UN personnel in communist prison camps, and the resultant necessity for prisoner exchanges made prosecution of war crimes trials impossible.
(2)Prosecution of spurious “war crimes trials” by totalitarian states, notably by the communists in Korea and, with respect to their own nationals, by the Castro government in Cuba.
(3)Failure of efforts initiated by the General Assembly to create an international criminal court which would obviate the problem of victor’s justice and of abuse of the concept of international criminal proceedings. The draft statute for such a court, prepared by the Committee on International Criminal Jurisdiction, was never voted upon, because the debate became interminably tied up with the question of the definition of aggression.
Genocide is a term first used during World War II. Of all the crimes defined at Nuremberg it is the most dreadful and universally condemned. The Genocide Convention of December 9, 1948, confirms that “…genocide, whether committed in time of peace or in time of war, is a crime under international law which the parties to the Convention undertake to prevent and punish.” Article n of the convention defines genocide as
…any of the following acts committed with intent to destroy, in whole or in part, a national, ethnic, racial, or religious group as such: (a) Killing members of the group; (b) Causing serious bodily or mental harm to members of the group; (c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (d) Imposing measures intended to prevent births within the group; (e) Forcibly transferring children of the group to another group. (Bishop  1962, p. 476)
Conspiracy, incitement, and complicity as regards genocide are also punishable under the convention. Parties to the convention are obliged to enact implementing legislation to assure punishment of persons guilty of this crime. Article VI provides that “persons charged with genocide or any of the other acts enumerated …shall be tried by a competent tribunal of the state in the territory of which the act was committed, or by such international penal tribunal as may have jurisdiction with respect to those contracting parties which shall have accepted its jurisdiction” (Bishop  1962, p. 476). Genocide is not considered a “political crime” for purposes of extradition (art. VII), and the parties agree to extradition of those accused of genocide in accordance with their own laws and treaties in force.
As of February 28, 1965, 67 nations had become signatories of the convention. However, no action has ever been taken under it.
Publicists who are noted as authorities on international criminal law as such have been and remain rare. Among the pioneers who developed the field in the interwar period were Donnedieu de Vabres (whose “Le procés de Nuremberg devant les principes modernes du droit pènal international”  summarizes the work of a career capped by service as a judge at Nuremberg), Pella (1930), and Sottile (1938). The post-World War II period saw an outburst of research and writing connected with all of the crimes punished at Nuremberg. Authoritative analysis of the war crimes trials is to be found in such works as those of Oppenheim ([1905-1906] 1948-1952), Bishop (1953), Stone (1954), McDougal and Feliciano (1961), Friedmann (1964), and Dahm (1958-1961). These also contain valuable assessments of the other subjects germane to international criminal law, such as human rights, genocide, and so on.
However, the apparent conviction that war crimes trials will not often be possible in contemporary conflicts has produced declining interest in this subject. It is notable that whereas the war-crimes literature in English is voluminous, English-language works on international criminal law as such are extremely rare. The subject seems to have attracted primarily Europeans and Latin Americans. Aroneanu (1961), Graven (1950), and Drost (1959), as well as García Mora (1962) and Quin-tano Ripollés (1952-1955), have been particularly concerned with crimes against humanity in the broad sense. But there are very few publicists like Glaser (1954) who have devoted themselves to the study of international criminal law as a comprehensive field within public international law (as distinct from comparative criminal law, about which a great deal is written).
One initiative worthy of note is that of García Mora (1962). He extends the concept of individual responsibility for crimes against the peace into the area of indirect aggression, which is of such significance in modern conflict.
International criminal law may develop in several directions. Friedmann calls attention to the “evolution of a new category of crime, which may be broadly defined as ‘economic crimes,’ variously defined in communist and western states, notably in West Germany” (see Friedmann 1964, p. 169). Closely related is the problem of extraterritoriality of antitrust law in an interdependent world (note particularly the pioneering work of Kronstein  on this subject). Obviously, it will be difficult to gain the same kind of consensus on this category of offenses that exists in principle with respect to war crimes. Another subject requiring more attention is that of extradition, which assumes the near universality of certain offenses.
Finally, international lawyers have only begun to probe the possibilities of an international criminal law to sanction possible future disarmament and arms control agreements. If such agreements materialize, adhering states will undoubtedly be obliged to develop, to a hitherto unaccomplished degree, the concepts of the world public order and of the impermissibility of offenses against it (see especially McDougal & Feliciano 1961).
William V. O’Brien
[See also Human Rights; International Law.Other relevant material may be found in Criminal Law; Political Justice.]
Aroneanu, Eugene 1961 Le crime contre I’ humanite’ . Paris: Dalloz.
Bishop, William W. (editor) (1953) 1962 International Law Cases and Materials. 2d ed. Boston: Little.
Clark, William L.; and Marshall, William L. (1900) 1952 A Treatise on the Law of Crimes. 5th ed. Chicago: Callaghan.
Dahm, Georg 1958-1961 Völkerrecht. 3 vols. Stuttgart (Germany): Kohlhammer.
Donnedieu De Vabres, Henri F. 1947 Le procés de Nuremberg devant les principes modernes du droit penal international. The Hague, Academy of International Law, Recueil des cours 70:481-580.
Drost, Pieter N. 1959 The Crime of State: Penal Protection for Fundamental Freedoms of Persons and Peoples. 2 vols. Leiden (Netherlands): Sythoff. → Volume 1: Humanicide: International Governmental Crime Against Individual Human Rights. Volume 2: Genocide: United Nations Legislation on International Criminal Law.
Friedmann, Wolfgang G. 1964 The Changing Structure of International Law. New York: Columbia Univ. Press.
García Mora, Manuel R. 1962 International Responsibility for Hostile Acts of Private Persons Against Foreign States. The Hague: Nijhoff.
Glaser, Stefan 1954 Introduction á I’ étude du droit international penal. Brussels: Bruylant.
Graven, Jean 1950 Les crimes contre I’ humanité. The Hague, Academy of International Law, Recueil des cours 76:429-606.
International Military Tribunal 1947-1949 Trial of the Major War Criminals Before the International Military Tribunal. 42 vols. Nuremberg (Germany): The Tribunal.
Kronstein, Heinrich D. 1962 Recht und wirtschaft-liche Macht: Ausgewählte Schriften. Karlsruhe (Germany): Müller. → Contains contributions in English and German.
Mcdougal, Myres S.; and Feliciano, Florentino P. 1961 Law and Minimum. World Public Order: The Legal Regulation of International Coercion. New Haven: Yale Univ. Press.
O’brien, William V. 1960 Legitimate Military Necessity in Nuclear War. World Polity: A Yearbook of Studies in International Law and Organization 2:35-120.
Oppenheim, Lassa F. L. (1905-1906) 1948-1952 International Law: A Treatise. 2 vols. 7th ed. London and New York: Longmans. → Volume 1: Peace. Volume 2: Disputes, War and Neutrality. Edited by Hersch Lauterpacht.
Pella, Vespasian V. 1930 La répression des crimes contre la personality de l’ etat. The Hague, Academy of International Law, Recueil des cours 33:673-830.
Quintano Rtpolles, Antonio 1952-1955 Tratado de derecho penal internacional e internacional penal. 2 vols. Madrid. Consejo Superior de Investigaciones Cientificas, Instituto “Francisco de Vitoria.”
Sottile, Antoine 1938 Le terrorisme international. The Hague, Academy of International Law, Recueil des cours 65:87-184.
Stone, Julius (1954) 1959 Legal Controls of International Conflict: A Treatise on the Dynamics of Disputes- and War-law. Rev. New York: Rinehart. → Includes a supplement for 1953-1958.
Un War Crimes Commission 1947-1949 Law Reports of Trials of War Criminals. 15 vols. London: H.M. Stationery Office.