|Decision on Command Responsibility - 16.07.2003||
HADŽIHASANOVIĆ et al.
35. […] The obligation of the Tribunal to rely on customary international law excludes any necessity to cite conventional law where customary international law is relied on. […]
44. […] [I]t has always been the approach of this Tribunal not to rely merely on a construction of the Statute to establish the applicable law on criminal responsibility, but to ascertain the state of customary law in force at the time the crimes were committed.
See also paragraph 55.
 See Ojdanić Decision, paras. 9-10.
 See Prosecutor v. Milutinović, Sainović & Ojdanić, Case No. IT-99-37-AR72, “Decision on Dragolub Ojdanić’s Motion Challenging Jurisdiction—Joint Criminal Enterprise,” 21 May 2003, para. 9 (“The scope of the Tribunal’s jurisdiction ratione materiae may therefore said to be determined both by the Statute, insofar as it sets out the jurisdictional framework of the International Tribunal, and by customary international law, insofar as the Tribunal’s power to convict an accused of any crime listed in the Statute depends on its existence qua custom at the time this crime was allegedly committed.”). See also Čelebići Appeal Judgment, para. 178.
|Interlocutory Decision on Jurisdiction - 02.10.1995||
Download full document
143. […] It should be emphasised again that the only reason behind the stated purpose of the drafters that the International Tribunal should apply customary international law was to avoid violating the principle of nullum crimen sine lege in the event that a party to the conflict did not adhere to a specific treaty. (Report of the Secretary-General, at para. 34.) It follows that the International Tribunal is authorised to apply, in addition to customary international law, any treaty which: (i) was unquestionably binding on the parties at the time of the alleged offence; and (ii) was not in conflict with or derogating from peremptory norms of international law, as are most customary rules of international humanitarian law. […]
|ICTY Statute Article 3|
|Appeal Judgement - 17.12.2004||
KORDIĆ & ČERKEZ
41. The Appeals Chamber notes that the Trial Chamber considered that Article 3 of the Statute covers not only violations which are based in customary international law but also those based on treaties. It found that Additional Protocol I constituted applicable treaty law in the present case, and found that “whether [Additional Protocol I] reflected customary law at the relevant time in this case is beside the point.”
42. The Appeals Chamber holds that the Trial Chamber’s approach is correct.
43. This approach is consistent with the language of Article 1 of the Statute granting the International Tribunal “competence to prosecute persons responsible for serious violations of international humanitarian law committed in the territory of the former Yugoslavia”. It is also consistent with Security Council Resolution 827 (1993) in which the Security Council expressed its determination “to take effective measures to bring to justice the persons who are responsible for [violations of international humanitarian law]”. These instruments do not impose any restriction to customary international law, which is in line with the statements made in the Security Council at the time the Statute was adopted.
44. The Trial Chamber’s approach is also in line with the Report of the Secretary-General in which he stated that:
the application of the principle nullum crimen sine lege requires that the international tribunal should apply rules of international humanitarian law which are beyond any doubt part of customary law so that the problem of adherence of some but not all States to specific conventions does not arise.
The maxim of nullum crimen sine lege is also satisfied where a State is already treaty-bound by a specific convention, and the International Tribunal applies a provision of that convention irrespective of whether it is part of customary international law.
 Trial Judgement, para. 167.
 Trial Judgement, para. 167.
 S/Res/827 (1993).
 See in particular the position expressed by the representatives of France: “Article 3 of the Statute covers specifically […] all the obligations that flow from the humanitarian law agreements in force on the territory of the former Yugoslavia”; United States: “’laws or customs of war’ referred to in Article 3 include all obligations under humanitarian law agreements in force in the territory of the former Yugoslavia”; United Kingdom: “The Statute does not, of course, create new law, but reflects existing international law in this field. In this connection, it would be our view that the reference to the laws or customs of war in Article 3 is broad enough to include applicable international conventions and that Article 5 covers acts committed in time of armed conflict”; Hungary: “the jurisdiction of the Tribunal covers the whole range of international humanitarian law”; Spain: “jurisdiction limited […] materially, in that it will be circumscribed to applying the international law in force”; Russian Federation: “Those guilty of mass crimes covered by the Geneva Protocols [sic], violations of the laws and customs of war, crimes of genocide and crimes against humanity must be duly punished” (Provisional Verbatim Record of the UN SCOR, 3217th Meeting, at 11, 15, 19, 20, 41, 44 U.N. Doc. S/PV.3217 (25 May 1993)). See also the position expressed by the representative of the Netherlands: “the Netherlands favours a system whereby the ad hoc tribunal would prosecute suspects on the basis of violations of substantive norms under international law,” (Note Verbale, dated 30 April 1993 from the Permanent Representative of the Netherlands to the United Nations addressed to the Secretary-General, U.N. Doc. S/25716 (4 May 1993)).
 Report of the Secretary-General, para. 34.
 The Appeals Chamber notes that Additional Protocol I and Additional Protocol II were ratified by the SFRY on 11 June 1979. Bosnia and Herzegovina deposited its Declaration of Succession on 31 December 1992, declaring it became party to the Geneva Conventions and the Additional Protocols as of the date of its independence, 6 March 1992. Croatia deposited its Declaration of Succession on 11 May 1992 and declared to be a party to the conventions to which the SFRY was a party as of 8 October 1991.
|Appeal Judgement - 30.11.2006||
Download full document
At paras 81-84, the Appeals Chamber clarified its position in that respect. It concluded:
85. […] while binding conventional law that prohibits conduct and provides for individual criminal responsibility could provide the basis for the International Tribunal’s jurisdiction, in practice the International Tribunal always ascertains that the treaty provision in question is also declaratory of custom.