by Penny Brouma, Member of the International Law Research Team

The maxim aut dedere aut judicare, deriving from the underlying idea of the maxim aut dedere aut punire, was originally formulated by Hugo Grotius in 1625 (Grotius, 1625). According to this principle, a State is required “either to deliver or to adjudge” individuals who have violated international criminal law (Fellmeth, A. & Horwitz, M., 2011). Essentially, if an alleged criminal is found in a given State, that State must choose between extraditing that individual for trial in another State or before an international criminal tribunal, or prosecuting the individual itself. Despite the original phrasing, punire cannot be considered as an alternative to dedere, as the modern version is designed to be more consistent with the fundamental principles of the presumption of innocence, nullum crimen sine lege and nulla poena sine lege or non bis in idem (Henzelin, M., 2000). 

According to the International Law Commission (ILC), the fundamental purpose of this principle is “to ensure that individuals who are responsible for particularly serious crimes are brought to justice by providing for the effective prosecution and punishment of such individuals by a competent jurisdiction” (Draft Code of Crimes against Mankind, 1996). 

The realization of the principle

The principle aut dedere aut judicare seems to provide States with an option, either to prosecute an alleged offender or to perform extradition. However, in any case, the State is bound to adopt one choice: “it must extradite if it does not prosecute, and prosecute if it does not extradite” (Tiribelli, C., 2009).  It is significant to emphasize that when speaking of prosecution, the obligation imposed by this principle is merely to submit the case to a State’s competent authorities, which are then to consider whether or not to prosecute (ICJ, Arrest Warrant case, para. 68, 2012). However, said discretion must be exercised in a bona fide manner (ICJ, Fisheries Case, Judge Alvarez Dis. Opinion, Sec. VI, 1951 & ICJ, Anglo-Iranian Oil, Judge Alvarez Dis. Opinion, Sec. V, 1952), meaning that the authorities make their decision in the same manner as in the case of any ordinary offence of a serious (or grave) nature under the law of that State, or that the proceedings be in accordance with the laws of the prosecuting State (Cheng B., 2006). Nevertheless, it is worth noting that Article 27 of the Vienna Convention on the Law of Treaties prohibits States from invoking national restrictions to justify incompliance with this international obligation (ICJ, LaGrand case, para. 79, 2001). Thereby, States should not exercise their discretionary rights unreasonably, in a way that frustrates the object and purpose of the principle (Kolb R., 2004).

The duty to extradite, on the other hand, is stipulated in clear and unequivocal language, which is commonly adopted in all international instruments on extradition. Specifically, “the Contracting Parties undertake to surrender to each other […] all persons against whom the competent authorities of the requesting Party are proceeding for an offence or who are wanted by the said authorities for the carrying out of a sentence or detention order” (European Convention on Extradition, 2005, Article 1). The effective fulfillment of said obligation requires a request, made pursuant to a bilateral or multilateral treaty between the two States, regulating the manner in which the surrender is to be carried out (Mitchell C., 2009).

Legal basis of the principle

The duty to extradite or prosecute is mainly established by virtue of a treaty, which may be multilateral or bilateral. 

Multilateral treaties cover very serious crimes such as crimes against humanity, various acts of terrorism, torture, enforced disappearances, corruption and organized crimes such as human and drugs trafficking. Said multilateral treaties aim to deal with the aforementioned offences through national prosecutions, facilitated by cooperation between governments. These include, but are not limited to, the 1948 UN Convention against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment, the 1948 Convention on the Prevention and Punishment of the Crime of Genocide, the 1949 Geneva Conventions and the 1977 Additional Protocol I, the 1954 Convention for the protection of Cultural Property in the event of armed conflict, the 1963 Tokyo Convention, the 1998 ISS Intergovernmental – Agreement and the 1999 Montreal Convention.  

With respect to bilateral treaties, these are typically required by most common law States, such as the the United Kingdom (Blackstone W., 1979) and the United States (Valentine v. United States, 1936, United States v. Fernandez-Morris, 1999, Elcock v. United States, 2000) which has over 150 extradition treaties in force alone. On the other hand, the practice of extradition in civil law–based systems is not necessarily predicated on an extradition treaty. 

Extradition may also be granted based on other legal bases, such as on the basis of national legislation, as well as treaties, reciprocity and comity. For instance, the principle aut dedere aut judicare has been incorporated in the penal law of numerous States, taking the form of national legislation, as in the cases of Azerbaijan, Finland, Colombia, Cape Verde, Estonia, Bosnia and Herzegovina, Kazakhstan, Korea, North Macedonia, Malta, Montenegro, Panama, Peru, Portugal, Serbia (Amnesty International, 2009). 

It can be argued that extradition is not considered  as a binding obligation by most States, in the absence of a treaty (Harvard Draft Convention on Extradition, 1935). However, there is a growing trend to recognize the duty to prosecute or extradite with respect to jus cogens crimes (Bassiouni, M. C., 1999). 

The principle as a customary rule

The legal status of the principle aut dedere aut judicare in the realm of international law constitutes quite a controversial subject. Specifically, there are different views as to whether such an obligation exists in customary international law. In order for it to qualify as a customary rule of international law, two elements are necessary, pursuant to Article 38 para. 1(b) of the Statute of the International Court of Justice; general State practice, which constitutes a material element, and opinio juris sive necessitatis, meaning the conviction that said State practice is “accepted as law”, which constitutes a subjective element. 

As aforementioned, there is no consensus upon the nature of this principle, however, more and more scholars are in favor of supporting the concept of aut dedere aut judicare as a general duty, based not only on the provisions of specific international treaties, but also on binding customary norms, at least concerning certain categories of crimes (ILC, 2006 & Stefanovska V., 2018).

Particularly, it has been supported that the prohibition of certain crimes under international law, such as genocide, crimes against humanity and war crimes, derive their authority from a peremptory norm (jus cogens) which allows for no derogation. The object of the obligation is to fight impunity and to ensure that perpetrators are brought to justice despite traditional obstacles.‎ Thus, any violation of jus cogens rules creates a corresponding obligation to the international community as a whole (erga omnes) either to institute criminal proceedings or to extradite the suspect to another competent State (Bassiouni, M.C., Wise E.M., 1995 & Goodwin-Gill, G.S., 1999). This originated from the Trial Chamber’s conclusion in the Furundžija case in the International Criminal Tribunal for the former Yugoslavia (ICTY), which noted that “one of the consequences of the jus cogens character bestowed by the international community upon the prohibition of torture is that every State is entitled to investigate, prosecute and punish or extradite individuals accused of torture who are present in a territory under its jurisdiction” (Prosecutor v. Furundžija, ICTY, para. 156, 1998).  In the same spirit, it was stated by the Supreme Court of Israel in the case of Eichmann, and echoed by a USA court in Demjanjuk, that “it is the universal character of the crimes in question which vests in every State the authority to try and punish those who participated in their commission” (District Court of Jerusalem, Israel v. Eichmann, paras. 11-13, 1962 & US Court of Appeals, Sixth Circuit, Demjanjuk v. Petrovsky, Sec. IV. C., 1985).

This view was also expressed by Judge Weeramantry, in his dissenting opinion in the Lockerbie case. His characterization of the principle aut dedere aut judicare as a rule of customary international law, seems to derive from the proposition that a state is entitled “to try its own citizens in the absence of an extradition treaty” (ICJ, Lockerbie Case, Judge Weeramantry Dis. Opinion, Sec. A, 1992). Thereby, pursuant to this view, such duty cannot be subject to the executive discretion of a State. (Bassiouni M.C., Wise E.M., 1995). 

Finally, pursuant to Rule 161 of the ICRC’s Customary International Humanitarian Law Study (International Committee of the Red Cross, 2014), which reflects customary international law, States must make every effort to cooperate, in order to facilitate the investigation of war crimes and the prosecution of the suspects. This includes extradition when requested. However, it can potentially be subject to conditions, namely those established by national legislation. 

However, despite persuasive arguments advanced by leading authorities in international criminal law to the contrary, (Bassiouni, M.C., Wise E.M., 1995) contemporary State practice indicates that there is no duty to extradite in the absence of a treaty (Wheaton H., 1916 & Plachta, M. 1999), even with respect to international offences (Lambert, J.J., 1990). According to this view, the principle aut dedere aut judicare constitutes a general principle of international law (Bassiouni, M.C., Wise, E., 1995, 57).

In 2011, the then Special Rapporteur Galicki, proposed a draft article on international custom as a source of the obligation aut dedere aut judicare. However, this was not well received by neither the Commission nor the Sixth Committee, emphasizing the lack of unanimity on the subject (Supplement No. 10 A/66/10 paras. 320, 326. & Doc. A/CN.4/650 para. 48).  

In addition, it was enshrined in the Lockerbie Case that extradition does not exist as an obligation in ‎international customary law (ICJ, Lockerbie Case, Declaration of Acting President Judge Oda, Sec. III, 1992).‎  

Furthermore, most States make extradition conditional on the existence of an extradition treaty, indicating that State practice requires a treaty for the realization of the principle. Thereby, extradition is considered to be a sovereign decision of the requested State,‎ which is under no ‎obligation to carry it out in the absence of an explicit provision to the contrary (Bassiouni, M.C., Wise E.M., 1995). Instead, a State is ‎given full discretionary power as to whether it should grant extradition. (Kyriakopoulos, G., 1999).  

Moreover, the analysis of Kriangsak Kittichaisaree, the chairman of the ILC’s Working Group on the subject of the obligation to extradite or prosecute, revealed that although a large number of States provide for universal jurisdiction for core crimes, only a few States have included the obligation to extradite implement in their national legislation (Kittichaisaree K., 2013). Besides, even regarding the existing multilateral treaties, a lack of consistency and uniformity has been observed. 

Thereby, there is insufficient State practice with respect to extradition to support the creation of a customary rule (Zgonec-Rožej M., Joanne Foakes J., 2013).

Even when the national laws of a State make extradition conditional on the existence of a treaty and there is no such treaty in force, most multilateral treaties provide the requested State with merely an “option” to consider the aforementioned multilateral treaty as the required legal basis. This kind of provision cannot be interpreted as obliging a State to extradite. 

In the Arrest Warrant case, Judges Higgins, Kooijmans and Buergenthal also briefly discussed the principle aut dedere aut judicare, declining to give a view on whether the aut dedere aut judicare obligation was one of treaty law or an obligation of customary international law (ICJ, Arrest Warrant case, paras. 46, 74, 2001). 

Jurisdiction of International Criminal Tribunals

The principle aut dedere aut judicare is closely related to the establishment of international criminal tribunals, as they share the same purpose; fighting impunity for international crimes. 

Criminal tribunals were first established under the auspices of the UN  Security Council with the creation of the International Criminal Tribunals for the former Yugoslavia and Rwanda. These tribunals constitute the predecessors of the International Criminal Court (ICC), established with the adoption of the Rome Statute. The Rome Statute establishes the complementary jurisdiction of the ICC in relation to that of a domestic court (Blokker, N., & Muller, S., 2002). This means that the ICC is unable to consider a case, which is being investigated or prosecuted by a State which has jurisdiction over it, unless the State is unwilling or unable genuinely to carry out the investigation or prosecution, pursuant to Article 17 of the Rome Statute. On the contrary, its predecessors, the International Criminal Tribunal for the former Yugoslavia and the International Criminal Tribunal for Rwanda retain primacy over the relevant offenders, although they have concurrent jurisdiction with national courts, according to Article 9 of the Statute of ICTY and Article 8 of the Statute of the ICTR. The jurisdiction of the ICC is based on the universality principle (Cassese A., 2003). 

In the case an alleged offender to be prosecuted in the ICC is located, the Court does not deliver an extradition request, but a  request for surrender under article 89 of the Rome Statute, with which a State party is required to comply. Additionally, should a situation arise where a State has received both a request for surrender under article 89 of the Rome Statute, and is obliged by an aut dedere aut judicare obligation to prosecute the competing treaty obligations are of equal weight.

Thereby, no one’s obligation has greater priority. Besides, prosecution by the ICC or a different international criminal tribunal would be consistent with the object of the principle (Pictet, J.S., 1958). 



Bassiouni, M.C., Wise E.M., 1995, Aut dedere aut judicare: The Duty to Extradite or Prosecute in International Law, Dordrecht/Boston/London: Martinus Nijhoff, p. 52.

Blackstone W., 1979, Commentaries on the Laws of England, p. 66, 67; Arnold D. McNair A.D., 1956, ‘International Law Opinions’ p.43.

Cassese A., 2003, International Criminal Law, Oxford, Oxford University Press, p. 285.

Cheng, B., 2006, General principles of law as applied by international courts and tribunals, Cambridge: Cambridge University Press, p.135.

Fellmeth, A. and Horwitz, M., 2011. Guide to Latin in international law. Oxford: Oxford University Press, 42.

Goodwin-Gill, G.S., 1999, “Crime in International Law: Obligations Erga Omnes and the Duty to Prosecute”, Guy S. Goodwin-Gill & Stefan Talmon (eds), The Reality of International Law: Essays in Honour of Ian Brownlie, Oxford: Clarendon Press, pp. 213, 220.

Grotius, De jure belli, Book II, Chapter XXI, para. IV (1).

Kolb R., 2004, “The Exercise of Criminal Jurisdiction over International Terrorists”, in Bianchi, A. (ed), Enforcing International Law Norms Against Terrorism, Oxford, Hart Publishing, p. 261.

Henzelin, M., 2000,  Le Principe de l’Universalité en Droit Pénal International: Droit et Obligation pour les États de Poursuivre et Juger selon le Principe de l’Universalité, Bâle/Genève/Munich: Helbing & Lichtenhahn et Bruxelles, 98-100.

Lambert, J.J., 1990, “Terrorism and Hostages in International Law”, Grotius Publications, p.190.

Mitchell, C, 2009, “The scope and operation of the obligation”, Aut Dedere, aut Judicare: The Extradite or Prosecute Clause in International Law, Graduate Institute Publications.

Pictet, J.S., 1958, Commentary: IV Geneva Convention Relative to the Protection of Civilian Persons in Time of War, Geneva, ICRC, p. 59.

Tiribelli, C., 2009, Aut dedere aut judicare: response to impunity in international criminal law, 21 Sri Lanka Journal of International Law 1, 232.


Bassiouni, M. C., 1999, “The Need for International Accountability”, in 3 International Criminal Law 3–30.

Blokker, N., & Muller, S., 2002, International Criminal Court. Hague Yearbook of International Law, 15, 173.

Galicki Z., 2011, Special Rapporteur, Second report on the obligation to extradite or prosecute (aut dedere aut judicare), Document A/CN.4/585; Document A/CN.4/648, para. 95.

In 1996 the United Nations Crime and Justice Information Network conducted a survey of extant bilateral extradition treaties.

Kittichaisaree K., 2013 Working Group on the Obligation to Extradite or Prosecute (aut dedere aut judicare), (Chairman’s informal working paper, 5 April).

Kyriakopoulos, G., 1999, “La sécurité de l’Aviation Civile en Droit International Publique”, p.126.

Plachta, M., 1999, “Aut dedere aut judicare: An overview of modes of implementation and approaches”, 6 Maastricht Journal of European and Comparative Law 4, 331-365.

Stefanovska, V., 2018, “Modern application of the principle aut dedere aut judicare in acts of terrorism and torture”, 56 Journal of Criminology and Criminal Law 3 (JCCL), p. 43-58.

Wheaton H., 1916, “Elements of International Law”, 51 ed., p. 188.

Zgonec-Rožej M., Joanne Foakes J., 2013, International Criminals: Extradite or Prosecute? Briefing paper, Chatham House, IL BP 2013/01.

Legal Instruments 

Draft Code of Crimes against the Peace and Security of Mankind with commentaries, 1996, commentary to Article 8, para.3. International Law Commission, Report of the International Law Commission on the Work of its Forty-Eighth Session, 51 U.N. G.A.O.R. Supp. (N.10) at 9, U.N. Doc. A/51/10 (1996) Available here.

European Convention on Extradition (2005) entered into force June 29, Article 1.

Harvard Draft Convention on Extradition, 1935, 29 Amsterdam Journal of  International Law 21, 30.

Rome Statute of the International Criminal Court, UN Doc. No. A/CONF.183/9, 17 July 1998 as corrected by process-verbaux of 10 November 1998, 12 July 1999, 30 November 1999, 8 May 2000, 17 January 2001 and 16 January 2002.

Statute of the International Criminal Tribunal for the Former Yugoslavia, 25 May 1993, UN Doc. S/RES/827 (1993) 

Statute of the International Tribunal for Rwanda, 8 November 1994, UN Doc. No. S/RES/955 (1994) 

Statute of the International Court of Justice, entered into force 18 April 1946

Vienna Convention on the Law of Treaties, entered into force Jan. 27, 1980, 1155 U.N.T.S. 331.

Other Documentation 

Amnesty International, 2009, International Law Commission: The obligation to extradite or prosecute. London, UK: Amnesty International Publications, pp.11-16.

International Committee of the Red Cross, 2014, “Cooperation in extradition and judicial assistance in criminal matters”, Advisory Service on International Humanitarian Law, p.1.

International Law Commission, 2006, Document A/CN.4/572, p.266. 

Official Records of the General Assembly, Sixty sixth Session, Supplement No. 10 (A/66/10), paras. 320 326.

Topical summary of the discussion held in the Sixth Committee of the General Assembly during its Sixty sixth Session, prepared by the Secretariat (Doc. A/CN.4/650), para. 48.


Anglo-Iranian Oil Co.,  (United Kingdom v. Iran) 1952 I.C.J. 133 (Jul. 22), Judge Alvarez dissenting opinion. Available here

Attorney-General of the Government of Israel v. Adolf Eichmann (Israel Sup. Crt, 1962) 36 I.L.R. 298, paras. 11-13. Available here.

Case concerning questions of interpretation and application of the 1971 Montreal Convention arising from the aerial incident at Lockerbie (Libyan Arab Jamahiriya v. USA) (Order) 1992, I.C.J., 117 (Apr. 14) 

Judge Weeramantry dissenting opinion. Available here.

Declaration of Acting President Judge Oda. Available here.

Fisheries Case, 1951, (United Kingdom v. Norway) (Judgement) I.C.J. 150 (Dec. 18), Judge Alvarez dissenting opinion; Available here.

In the Matter of the Extradition of John Demjanjuk, 612 F. Supp.544, 558 (N.D. Ohio 1985); Demjanjuk v. Petrovsky, 776 F. 2d 571 (6th Cir. 1985), Sec. IV. C., cert. denied, 475 U.S. 1016, 106 S. Ct. 1198, 89 L. Ed. 2d 312 (1986); Available here.

LaGrand Case, 2001, (Germany v. United States of America) (Judgment) I.C.J., para. 79, p. 475 (June 27). Available here.

Questions relating to the obligation to prosecute or extradite, 2012, (Belgium v. Senegal) (Judgement) I.C.J. 451. Available here.

Questions relating to the obligation to prosecute or extradite, 2012, (Belgium v. Senegal) (Joint separate opinion of Judges Higgins, Kooijmans and Buergenthal) I.C.J. paras 46, 74. Available here.

Prosecutor v. Furundžija, ICTY Trial Chamber, Case No. IT-95-17/1-T, Judgement, para. 156 (Dec. 10, 1998). Available here.

Valentine v. United States ex rel. Neidecker, 299 U.S. 5 (1936); Factor v. Laubenheimer, 290 U.S. 276 (1933); United States v. Rauscher, 119 U.S. 407 (1886); Holmes v. Jennison, 39 U.S. 540 (1840); 4 Hackworth Digest 11; 6 Whiteman Digest 732; Elcock v. United States, 80 F. Supp. 2d 70 (E.D.N.Y. 2000); United States v. Fernandez-Morris, 99 F. Supp. 2d 1358 (S.D. Fla. 1999).