Defining an International Crime: Historical and Contemporary Developments

  • Amade Roberts Amana, PhD Kampala International University in Tanzania
  • Funmilola Akinremi Joseph Ayo Babalola University
Keywords: International Crime, Definition, Transnational Crime, International Law Commission, International Criminal Court
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Despite the desirability of the identity of crimes being specific, the category of conduct constituting international crimes remains blurry. In consequence, the controversy over what is, or is not, an international crime has continued to rage on. Different criteria have been used to classify a specific conduct as an international crime. As a source of authority, some authorities point to the works of scholars, treaties, legal systems, the statutes of international criminal courts, or even works of the International Law Commission, to identify an international crime. Nevertheless, unanimity in identification remains elusive. Thus, this article examines differing perspectives on the constituents of international crimes. The analysis is relevant because the definition of crime forms the bedrock of international criminal justice. However, the paper finds that leaving the category of conducts constituting an international crime open, facilitates the inclusion of other grave or emerging forms of criminality, which may also rise to the threshold of the crimes within the jurisdiction of international criminal tribunals. Although this may appear advantageous, the need for predictability, consistency and uniformity in the categorization of an international crime cannot be overemphasized


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UN Security Council resolution 1664 (2006), 29 March 2006.

By the Rome Statute of the ICC Article 123, 7 years after the entry into force of the Statute, the Secretary-General of the United Nations shall convene a Review Conference to consider any amendments to the Statute, and such review may include, although not limited, the list of crimes contained in Article5.

Principles of International Law Recognized in the Charter of the Nürnberg Tribunal and in the Judgment of The Tribunal, 1950.

J Harrison, ‘The International Law Commission and the Development of International Investment Law’ (2013) Vol. 45 The George Washington International Law Review, 417.

Statute of the International Law Commission Article 1, United Nations General Assembly Resolution A/RES/174(II) 21 November 1947.

B B Ferencz, ‘The Draft Code of Offences against the Peace and Security of Mankind’ (1981) Vo. 75. No. 3 The American Journal of International Law, 674.

Article 1 of the 1954 Draft Code provides that offences against the peace and security of mankind, as defined in this Code, are crimes under international law, for which the responsible individual must be punished”. By Article 2 of the Code, the offences are: (1) Any act of aggression, including the employment by the authorities of a State of armed force against another State; (2) Any threat by the authorities of a State to resort to an act of aggression against another State; (3) The preparation by the authorities of a State of the employment of armed force against another State for any purpose other than self-defence, or a decision of the United Nations; (4) The organization, or the encouragement of the organization, by the authorities of a State, of armed bands within its territory or any other territory for incursions into the territory of another State…; (5) The undertaking or encouragement by the authorities of a State of activities calculated to foment civil strife in another State…; (6) The undertaking or encouragement by the authorities of a State of terrorist activities in another State, or the toleration by the authorities of a State of organized activities calculated to carry out terrorist acts in another State; (7) Acts by the authorities of a State in violation of its obligations under a treaty which is designed to ensure international peace and security by restrictions or limitations on armaments…; (8) The annexation by authorities of a State of territory belonging to another State…; (9) The intervention by the authorities of a State in the internal or external affairs of another State, by means of coercive measures of an economic or political character in order to force its will and thereby obtain advantages of any kind; (10) Acts by the authorities of a State or by private individuals committed with intent to destroy , in whole or in part, a national, ethnic, racial or religious group as such, including (i) Killing members of the group; (ii) Causing serious bodily or mental harm to members of the group; (iii) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (iv) Imposing measures intended to prevent births within the group; and (v) Forcibly transferring children of the group to another group; (11) Inhuman acts such as murder, extermination, enslavement, deportation or persecutions committed against any civilian population on social, political, racial, religious or cultural grounds by the authorities of a State or by private individuals acting at the instigation or toleration of such authorities; (12) Acts in violation of the laws or customs of war; (13) Acts which constitute conspiracy, direct incitement, complicity, or attempts to commit any of the preceding offences.

By virtue of Principle 2 of the Princeton Principles on Universal Jurisdiction 2001, serious crimes under international law includes piracy, slavery, war crimes, crime against peace, crimes against humanity, genocide, and torture.

Donald M. Ferencz, (2017) ‘Continued Debate Over the Crime of Aggression: A Supreme International Irony’, Vol. 58. Online Journal, Harvard International Law Journal, p. 24, range 24-27.

Garner (n4 supra), p. 891.

Indictable offences are the more serious crimes, e.g., murder, theft, perjury, the trial of which takes place in the crown court. Summary or petty offences are those which must be tried summarily, i.e., before a magistrates’ court, where there is no jury. Arrestable are offences for which the sentence is fixed by law or for which a person, not previously convicted, may under or by virtue of any enactment be sentenced to imprisonment for a term of five years… All other offences are generally non-arrestable offences. A felony was an offence which had been made such by statute, or which, at common law, carried on conviction, the penalties of death and forfeiture. All other offences were misdemeanours. L B Curzon, Criminal Law (3rd edn, Plymouth: MacDonald & Evans Ltd, 1980) pp. 11-12.

Draft Articles on the Responsibility of States for Internationally Wrongful Acts, Report of the ILC on the Work of its Fifty-third Session, UN GAOR, 56th Session, Supp. No. 10, p. 43, UN Doc A/56/10 (2001).

See for instance, Article 19 of the 1996 ILC Draft Articles on State Responsibility.

UNGA 222; A/RES/42/151 (7 December 1987)

Namely, the threat of aggression; intervention; colonial domination and other forms of alien domination; apartheid; the recruitment, use, financing and training of mercenaries; and willful and severe damage to the environment. This was done in response to strong criticism from some governments over the inclusion of the crimes.

Yearbook of the International Law Commission, 1995, vol. II (Part Two), paras. 38 and 39.

Text adopted by the International Law Commission at its forty-eight session, in 1996, and submitted to the General Assembly as part of the Commission’s covering the work of that session.

Article 16.

Article 17.

Article 18.

Under Article 19 (1), the following crimes constitute crimes against the peace and security of mankind when committed intentionally and in a systematic manner on a large scale against United Nations and associated personnel involved in a United Nations operation with a view to preventing or impeding that operation from fulfilling its mandate: (a) murder, kidnapping or other attack upon the person or liberty of any such personnel; (b) violent attack upon the official premises, the private accommodation or the means of transportation of any such personnel likely to endanger his or her persons or liberty. (2). This article shall not apply to a United Nations operation authorized by the Security Council as an enforcement action under Chapter VII of the Charter of the United Nations in which any of the personnel are engaged as combatants against organized armed forces and to which the law of international armed conflict applies.

Article 20.

Year Book of the International Law Commission, 1996, Vol. II (Part Two), para. 46.

United Nations General Assembly A/RES/44/39, 72nd Plenary Session, 4th December 1989.

Draft Statute for an International Criminal Court with Commentaries, 1994. Report of the International Law Commission on the work of its forty-sixth session submitted to the United Nations’ General Assembly.

In summary, the crimes pursuant to treaties (in Article 20 (e)) are (1) Grave breaches of the four GenevaConventions of 1949 and Additional Protocol I; (2) The unlawful seizure of aircraft as defined by Article1 of the Convention for the Unlawful Seizure of Aircraft of 16th December 1970; (3) The crimes defined by Article 1 of the Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation of 23rd September 1971; (4) Apartheid and related crimes as defined by Article II of the International Convention on the Suppression and Punishment of the Crime of Apartheid of 30th November 1973; (5) The crimes defined by Article 2 of the Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons, Including Diplomatic Agents of 14th December 1973; (6) Hostage-taking and related crimes as defined by Article 1 of the International Convention against the Taking of Hostages of 17th December 11979; (7) The crime of torture made punishable pursuant to Article 4 of the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment of 10th December 1984; (8) The crimes defined by Article 3 of the Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation and by Article 2 of the Protocol for the Suppression of Unlawful Acts against the Safety of Fixed Platforms located on the Continental Shelf, both of 10th March 1988; and (9) The crimes of illicit traffic in narcotic drugs and psychotropic Substances of 20th September 1988 which, having regard to Article 2 of the Convention are crimes with international dimensions.

Protocol on Amendments to the Protocol on the Statute of the African Court of Justice and Human and Peoples’ Rights, adopted on 27th June 2014, Article 28A: 1. Subject to the right of appeal, the International Criminal Law Section of the Court shall have power to try persons for the crimes provided hereunder: (1) Genocide; (2) Crimes Against Humanity; (3) War Crimes; (4) The Crime of Unconstitutional Change of Government; (5) Piracy; (6) Terrorism; (7) Mercenarism; (8) Corruption; (9) Money Laundering; (10) Trafficking in Persons; (11) Trafficking in Drugs; (12) Trafficking in Hazardous Wastes; (13) Illicit Exploitation of Natural Resources; and (14) The Crime of Aggression.

The Assembly may extend upon the consensus of States Parties the jurisdiction of the Court to incorporate additional crimes to reflect developments in international law.

Abass, ‘Prosecuting International Crimes in Africa: Rationale, Prospects and Challenges’ (2013) Vol. 24.No. 3. The European Journal of International Law, 939.

A Cassese, International Criminal Law (2nd ed, Oxford: Oxford University Press, 2008) p. 11.

Ibid pp. 11-12. See also T Einarsen, The Concept of Universal Crimes in International Law (Oslo: Torkel Opsahl Academic EPublisher, 2012) p. 151.

Cassese, (n 41) p. 12.

R Cryer et al, An Introduction to International Criminal Law and Procedure (Cambridge: Cambridge University Press, 2007) p. 2.


Ibid p. 4.

Ibid p. 5.


W A Schabas, An Introduction to the International Criminal Court (Cambridge: Cambridge University Press, 2004) p. 26.


J Howard, ‘Invoking State Responsibility for Aiding the Commission of International Crimes-Australia, The United States of America and the Question of East Timor’ (2001) Vol. 2 No. 1. Melbourne Journal of International Law, 1.

Howard, op cit.

The Code was intended to serve as the jurisdictional basis for both domestic courts and the permanent international criminal court. Article 8 of the Draft Code of Crimes against the Peace and Security of Mankind provides that “Without prejudice to the jurisdiction of an international criminal court, each state party shall take such measures as may be necessary to establish its jurisdiction over the crimes set out in Arts. 17 (genocide), 18 (crimes against humanity), 19 (crimes against the United Nations and associated personnel), and 20 (war crimes), irrespective of where, or by whom these crimes were committed. Jurisdiction over the crime set out in Article16 (aggression) shall rest with an international criminal court...”

E A Oji, Responsibility for Crimes under International Law (Lagos: Odade Publishers, 2013) p. 7

It is worthy to recall that the Princeton Project on Universal Jurisdiction is a project sponsored by the International Commission of Jurists and is a combined effort of eminent scholars and jurists to formulate principles in order to clarify this area of international law.

A A C Trindade, ‘Jus Cogens: The Determination and Gradual Expansion of Its Material Content in Contemporary International Case Law’ (2012) 12. http://www/ accessed on 2 May 2022.

ISIS/ISIL in Syria is said to have received support in funds, etc from some Middle-East States.

Garner, (n 4), p. 1251, defines ‘peremptory’ as ‘final; absolute; conclusive; Incontrovertible. Not requiring any cause shown; arbitrary.’

M C Bassiouni, ‘A Functional Approach to “General Principles of International Law’ (1989) 11 Michigan Journal of International Law, 768.

I Brownlie, Principles of Public International Law (Fifth edn, Oxford: Clarendon Press, 1998) p. 515.

R Nieto-Navia, ‘International Peremptory Norms (Jus cogens) and International Humanitarian Law’. Man’s Inhumanity to Man: Essays on International Law in honour of Antonio Cassese. (The Hague: Kluwer Law International, 2003) pp. 595-640.

H Grotius held that there existed certain ‘principles’ amounting to jus naturale necessarium (necessary natural law).

C Wollf, ‘Jus Gentium’ (1764), para. 5.

E de Vattel, ‘Le Droit des Gens ou Principes de la Loi Naturale’ (1758), para. 9.

In 1905, Oppenheim opined that ‘a number of universally recognized principles’ of international law existed which rendered any conflicting treaty void and that the peremptory effect of such principles was itself a ‘unanimously recognized customary rule of international law’. See M Byers, ‘Conceptualizing the Relationship between Jus cogens and Erga Omnes Rules’ (1977) 66 Nordic Journal of International law 213, referring to L Oppenheim, International law Vol. 1 (London: Longmans, 1905) p. 528.

Covenant of the League of Nations, 1919 Article 20.1. Interpreting Article 20.1 of the Covenant in The Oscar Chinn Case (1934) PCIJ Rep. Ser. A/B, No. 63, p. 149, Judge Schucking held that ‘the covenant of the League of Nations, as a whole , and more particularly its Article 20…would possess little value unless treaties concluded in violation of that undertaking were to be regarded as absolutely null and void,..And I can hardly believe that the League of Nations would have already embarked on the codification of international law if it were not possible, even today, to create a jus cogens, the effect of which would be that, once States have agreed on certain rules of law, and have also given an undertaking that these rules may not be altered by some only of their number, any act adopted in contravention of that undertaking would be automatically void’.

M C Bassiouni, Crimes against Humanity: Historical Evolution and Contemporary Application (New York: Cambridge University Press, 2011) p. 266. See also Case of The SS. Wimbledon, PCIJ 17th August 1923, p. 25.

Case Concerning the Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America), 1986 ICJ. 14, 95 (27th June) (concerning the applicability of the Vienna Convention on the Law of Treaties). The VCLT with annex, 23rd May 1969, U.N. A/Conf. 39/27. However, Article 71, paragraph 1 (a) makes it clear that the entire treaty is not null and void if the parties do not give effect to the provision in question. The ICJ has also considered the question. In U.S. Diplomatic and Consular Staff in Tehran (U.S V Iran), 1980 I.C.J. 3 (May 24), the court holds that some treaty obligations can also be ‘obligations under general international law’, and in its advisory opinion on the Reservations to the Convention on Genocide 1951 I.C.J. 15 (May 28), it holds that the Genocide Convention is part of customary law.

The Prosecutor v Anto Furundzij (ICTY Trial Chamber), 10th December 1998, paras. 137, 144-157.

Restatement (Third) of Foreign Relations of the United States 702 cmts. d –I, 102 cmt. k (1987).

H Fujita, ‘The Advisory Opinion of the International Court of Justice on the Legality of Nuclear Weapons’ (1997) No. 316 International Review of the Red Cross.

Agreement for the Prosecution and Punishment of Major War Criminals of the European Axis, 8th August 1945, London Charter, 59 Stat. 1544, 82 U.N.T.S. 279.

A Memeti and B Nuhija, ‘The Concept of Erga Omnes Obligations in International Law’ (2013) No. 14 New Balkan Politics: Journal of Politics.

Eric A. Posner ‘Erga Omnes Norms, Institutionalization, and Constitutionalism in International Law’ (2008) John M. Olin Law and Economics Working Paper 2nd Series, Public Law and Legal Theory Working Paper No. 224, The Law School of the University of Chicago, p. 2.


Bassiouni has argued that it may be true that all jus cogens norms of international law give rise to erga omnes obligations, but the converse that all norms from which erga omnes obligations flow are jus cogens is questionable. For example, arguably all customary human rights norms carry with them erga omnes obligations, yet all have certainly not reached the status of jus cogens. M C Bassiouni, International Crimes: Jus Cogens and Obligatio Erga Omnes (1996) Vol. 58 No. 4 Law and Contemporary Problems, 63

In Right of Passage over Indian Territory (Portugal v India) (Merits), 1960 ICJ 123, 135 (12th April) (Fernandes, J. dissenting), Judge Fernandes stated that it is true that in principle, special rules will prevail over general rules, but to take it as established that in the present case the particular rule is different from the general is to beg the question. Moreover, there are exceptions to this principle... And the general principles to which I shall refer later constitute true rule of jus cogens over which no special practice can prevail.

S.S ‘Lotus’ (France V. Turkey), 1927 P. C.I.J (ser. A) No. 10 (Sept. 7).

Bassiouni (1996), op cit, p. 74.

N Boister, ‘Transnational Criminal Law?’ (2003) Vol. 14. No. 5. European Journal of International Law, 967-77.

The United Nations Convention against Transnational Organized Crime, 15th November 2000. And the Palermo Protocols: (1) Protocol to Prevent, Suppress and Punish Trafficking in Persons, especially Women and Children (2) Protocol against the Smuggling of Migrants by Land, Sea and Air (3) Protocol against the Illicit Manufacturing and Trafficking in Firearms.

th December 2000, in force 25th December 2003.

th December 2000, in force 28th January 2004.

th July 2001, in force 3rd July 2005.

Money laundering; terrorist activities; theft of art and cultural objects; theft of intellectual property; illicit arms trafficking; aircraft hijacking; sea piracy; land hijacking; insurance fraud; computer crime; environmental crime; trafficking in persons; trade in human body parts; illicit drug trafficking; fraudulent bankruptcy; infiltration of legal business; corruption and bribery of public officials as defined in national legislation; and other offences committed by organized criminal groups. See the Ninth United Nations Congress on the Prevention of Crime and the Treatment of Offenders, Cairo, Egypt, 29th April -8th May 1995; A/CONF. 169/15/Add. 1.

15 April, 2024
How to Cite
Amana, A., & Akinremi, F. (2024). Defining an International Crime: Historical and Contemporary Developments. East African Journal of Law and Ethics, 7(1), 15-28.