1 The decision was delivered orally on 12 June 2009: Prosecutor v. Katanga and Ngudjolo, ICC-01/04-01/07-T-67-ENG ET, 12 June 2009. Written reasons were subsequently delivered on 16 June 2009 in Prosecutor v. Katanga and Ngudjolo, Reasons for the Oral Decision on the Motion Challenging the Admissibility of the Case (Article 19 of the Statute), ICC-01/04-01/07-1213-tENG, 16 June 2009 (hereinafter Katanga Admissibility Decision).

2 In addition to the specific discussion of ‘positive complementarity’ (see infra, notes 89 to 101), see, e.g., M. El Zeidy, The Principle of Complementarity in International Criminal Law (2008); J. Stigen, The Relationship between the International Criminal Court and National Jurisdictions: The Principle of Complementarity (2008); J. Kleffner, Complementarity in the Rome Statute and National Criminal Jurisdictions (2008); H. Olasolo, The Triggering Procedure of the International Criminal Court (2005); J. Holmes, ‘Complementarity: National Courts vs. the ICC’, in A. Cassese et al. (eds.), The Rome Statute of the International Criminal Court: A Commentary (2002); Burke-White, W. and Kaplan, S., ‘Shaping the Contours of Domestic Justice: The International Criminal Court and the Admissibility Challenge in the Ugandan Situation’, (2009) 7 Journal of International Criminal Justice 257CrossRefGoogle Scholar; Greenawalt, A., ‘Complementarity in Crisis: Uganda, Alternative Justice, and the International Criminal Court’ (2009) 50 Virginia Journal of International Law 107Google Scholar; Martin, J., ‘The International Criminal Court: Defining Complementarity and Divining Implications for the United States’ (2006) 4 Loyola University Chicago International Law Review 107Google Scholar; Mégret, F., ‘In Defense of Hybridity: Towards a Representational Theory of International Criminal Justice’ (2005) 38 Cornell International Law Journal 725Google Scholar; Yang, L., ‘Article on the Principle of Complementarity in the Rome Statute of the International Criminal Court’, (2005) 4 Chinese Journal Of International Law 121CrossRefGoogle Scholar; M. Arsanjani and M. Reisman, ‘The Law-in-Action of the International Criminal Court’, (2005) 99 AJIL 385; Benzing, M., ‘The Complementarity Regime of the International Criminal Court: International Criminal Justice between State Sovereignty and the Fight against Impunity’, (2003) 7 Max Planck Yearbook of United Nations Law 591CrossRefGoogle Scholar; Kleffner, J., ‘The Impact of Complementarity on National Implementation of Substantive International Criminal Law’ (2003) 1 Journal of International Criminal Justice 86CrossRefGoogle Scholar; Zeidy, M. El, ‘The Principle of Complementarity: A New Machinery to Implement International Criminal Law’, (2002) 23 Michigan Journal Of International Law 869Google Scholar; Gurulé, J., ‘United States Opposition to the 1998 Rome Statute Establishing an International Criminal Court: Is the Court's Jurisdiction Truly Complementary to National Criminal Jurisdictions?’, (2001–2) 35 Cornell International Law Journal 1Google Scholar; Newton, M., ‘Comparative Complementarity: Domestic Jurisdiction Consistent with the Rome Statute of the International Criminal Court’, (2001) 167 Military Law Review 20Google Scholar.

3 In particular Prosecutor v. Ntaganda, Decision on the Prosecutor's Application for Warrants of Arrest, Article 58, ICC-01/04-02/06-20-Anx2, 21 July 2008, paras. 29–89; and Prosecutor v. Kony et al., Decision on the Admissibility of the Case under Article 19(1) of the Statute, ICC-02/04-01/05-377, 10 March 2009 (hereinafter Kony Admissibility Decision). Each of these proceedings also led to appeals: see Situation in the Democratic Republic of the Congo, Judgment on the Prosecutor's appeal against the decision of Pre-Trial Chamber I entitled ‘Decision on the Prosecutor's Application for Warrants of Arrest, Article 58’, ICC-01/04-169, 13 July 2006 (hereinafter Ntaganda Admissibility Appeal Judgment); Prosecutor v. Kony et al., Judgment on the appeal of the Defence against the ‘Decision on the Admissibility of the Case under Article 19(1) of the Statute’ of 10 March 2009, ICC-02/04-01/05-408, 16 September 2009 (hereinafter Kony Admissibility Appeal Judgment). See further B. Batros, ‘The Evolution of the ICC Jurisprudence on Admissibility’, in C. Stahn and M. El Zeidy (eds.), The International Criminal Court and Complementarity: From Theory to Practice (2010, forthcoming).

4 Art. 82(1)(a). Other decisions which may be appealed as of right include decisions on jurisdiction, detention, and release, and the decision of a pre-trial chamber to act on its own initiative under Art. 56(3); and a state may appeal the decision of a pre-trial chamber to authorize direct investigative steps on its territory under Art. 57(3)(d). Final decisions under Art. 74 and decisions on reparations under Art. 75 are also appealable directly.

5 Prosecutor v. Katanga and Ngudjolo, Judgment on the Appeal of Mr Germain Katanga against the Oral Decision of Trial Chamber II of 12 June 2009 on the Admissibility of the Case, ICC-01/04-01/07-1497 OA8, 25 September 2009 (hereinafter Katanga Admissibility Appeal Judgment).

6 Prosecutor v. Katanga and Ngudjolo, Motion Challenging the Admissibility of the Case by the Defence of Germain Katanga pursuant to Article 19(2)(a) of the Statute, ICC-01/04-01/07-949, 11 March 2009 (hereinafter Katanga Admissibility Challenge). The challenge was originally filed confidentially and ex parte on 10 February 2009, and was made available to the other parties on 25 February 2009.

7 Ibid., para. 28.

8 Ibid., paras. 29–44. Rather, Katanga argued that the objective of complementarity required that admissibility be determined based on a broader test, such as ‘comparative gravity’ or ‘comprehensive conduct’ (ibid., paras. 46–47, 51). For further discussion of the background to and content of the ‘same conduct’ test, see Batros, supra note 3.

9 Ibid., paras. 11–12 (also including genocide, and in one instance war crimes); Prosecutor v. Katanga and Ngudjolo, Defence Reply to Prosecution Response to Motion Challenging the Admissibility of the Case by the Defence of Germain Katanga pursuant to Article 19(2)(a), ICC-01/04-01/07-1015, 1 April 2009 (hereinafter Katanga Admissibility Reply), paras. 4–5, 9, 14.

10 Katanga Admissibility Challenge, supra note 6, paras. 15, 38, 53; Katanga Admissibility Reply, supra note 9, paras. 6, 9, 14, 28.

11 In addition, Katanga subsequently argued that the DRC's decision to close its investigation on his transfer to the Court should be interpreted as a ‘decision not to prosecute’, which also rendered his case inadmissible under Art. 17(1)(b). Katanga Admissibility Reply, supra note 9, paras. 9–10.

12 Ibid., paras. 4–7, 11–14.

13 Prosecutor v. Katanga and Ngudjolo, Public Redacted Version of the 19th March 2009 Prosecution Response to Motion Challenging the Admissibility of the Case by the Defence of Germain Katanga pursuant to Article 19(2)(a), ICC-01/04-01/07-1007, 30 March 2009 (hereinafter Prosecution Response to Katanga Admissibility Challenge), paras. 103–107.

14 Ibid., paras. 51–96, 108.

15 See in particular Prosecution Response to Katanga Admissibility Challenge, supra note 13, paras. 69–74, 90–91.

16 Ibid., paras. 43, 109–110, and factual submissions referred to therein.

17 Prosecutor v. Katanga and Ngudjolo, observations écrites des autorités congolaises telles que présentées à l'audience du 1er juin 2009, ICC-01/04–01/07–1189-Anx-tENG, 16 July 2009, at 5; Prosecutor v. Katanga and Ngudjolo, Transcript of Hearing of 1 June 2009, ICC-01/04-01/07-T-65-ENG ET, at 78, lines 11–19; at 79, lines 18–21; at 81, lines 4–7; at 85, line 1–86, line 3; at 93, lines 14–16; at 94, line 12.

18 Katanga initially lodged his challenge to admissibility on 10 February 2009. The Presidency of the ICC had constituted Trial Chamber II and referred to it the case of Prosecutor v. Katanga and Ngudjolo some three and a half months earlier, on 24 October 2008 (Prosecutor v. Katanga and Ngudjolo, Decision constituting Trial Chamber II and referring to it the case of The Prosecutor v. Germain Katanga and Mathieu Ngudjolo Chui, ICC-01/04-01/07-729, 24 October 2008). At the time that the challenge was lodged, a date had not yet been set for the hearing of the trial to commence; however, in March 2009 the Trial Chamber set the date for the commencement of the hearing of the trial as 24 September 2009 (Prosecutor v. Katanga and Ngudjolo, Décision fixant la date du procès (règle 132–1 du Règlement de procédure et de preuve), ICC-01/04-01/07-999, 27 March 2009). That date was subsequently postponed until 24 November 2009 (Prosecutor v. Katanga and Ngudjolo, Décision reportant la date d'ouverture des débats au fond (règle 132–1 du Règlement de procédure et de preuve), ICC-01/04-01/07-1442, 31 August 2009).

19 Prosecutor v. Katanga and Ngudjolo, Transcript of 1 June 2009, ICC-01/04-01/07-T-65-ENG ET, at 27, line 23–28, line 23.

20 Ibid., at 29, lines 5–8, and at 45, line 12–46, line 2.

21 Katanga Admissibility Decision, supra note 1, paras. 49–50. Of the 95 paragraphs of the written reasons, the Trial Chamber devoted 33 paragraphs to the question of the timing of the challenge (paras. 7–8, 28–58).

22 Ibid., paras. 57–58. The Trial Chamber did so on the basis that the relevant provisions of the Statute and the Rules were vague, the defence was not aware that it was filing the challenge out of time, and that statements of the Pre-Trial Chamber may have led the defence to believe that it could bring the challenge before the Trial Chamber (see para. 56).

23 Ibid., paras. 59–73 (see in particular paras. 65–66, 69–71), referring to Ntaganda Admissibility Appeal Judgment, paras. 2, 52. See further Batros, supra note 3.

24 Katanga Admissibility Decision, supra note 1, para. 77.

25 Ibid., para. 95.

26 For example, in his fourth ground of appeal Katanga argued that the Trial Chamber had confused the concepts of ‘unwillingness’ and ‘inability’. The Appeals Chamber did not engage in the merits of this ground. In the light of its findings on the law and the facts in relation to the third ground of appeal (discussed below), the question of inability (or unwillingness, for that matter) simply did not arise in this case (Katanga Admissibility Appeal Judgment, supra note 5, paras. 89–91, 96–97).

27 Prosecutor v. Lubanga, Judgment on the appeal of Mr Thomas Lubanga Dyilo against the Decision of Pre-Trial Chamber I entitled ‘Décision sur la demande de mise en liberté provisoire de Thomas Lubanga Dyilo’, ICC-01/04-01/06-824 OA7, 13 February 2007, para. 71, and see also para. 43; Prosecutor v. Lubanga, Judgment on the Appeal of the Prosecutor against the Decision of Trial Chamber I Entitled ‘Decision on the Consequences of Non-disclosure of Exculpatory Materials Covered by Article 54(3)(e) Agreements and the Application to Stay the Prosecution of the Accused, Together with Certain Other Issues Raised at the Status Conference on 10 June 2008’, ICC-01/04-01/06-1486 OA13, 21 October 2008, para. 85.

28 Prosecutor v. Katanga and Ngudjolo, Document in Support of Appeal of the Defence for Germain Katanga against the Decision of the Trial Chamber ‘Motifs de la décision orale relative à l'exception d'irrecevabilité de l'affaire’, ICC-01/04-01/07–1279 OA8, 8 July 2009 (hereinafter Katanga Admissibility Appeal Brief), paras. 42–51. The document in question made reference to Bogoro in one of the applications to extend Katanga's detention in the DRC. Katanga Admissibility Decision, supra note 1, para. 68; see also paras. 70–71.

29 Katanga Admissibility Appeal Judgment, supra note 5, para. 57.

30 See Rules of Procedure and Evidence, Rules 154 and 155; Regulations of the Court, Regulations 64 and 65.

31 See Katanga Admissibility Appeal Judgment, supra note 5, para. 37, and previous judgments referred to therein.

32 Ibid., para. 57. The prosecution argued that this was especially the case given that the Trial Chamber had the documents in question before it, as well as all other potentially relevant documents, along with the full submissions of both Katanga and the DRC authorities. The Appeals Chamber also based its dismissal of this ground on the fact that the admissibility of a case must be determined on the basis of the facts as they exist at the time of the challenge (para. 56, examined in more detail below; see further Batros, supra note 3.

33 Katanga Admissibility Appeal Brief, supra note 28, para. 41.

34 Katanga Admissibility Appeal Judgment, supra note 5, para. 38.

35 Ibid., para. 38.

36 Situation in the Democratic Republic of the Congo, Judgment on Victim Participation in the Investigation Stage of the Proceedings in the Appeal of the OPCD against the Decision of Pre-Trial Chamber I of 7 December 2007 and in the Appeals of the OPCD and the Prosecutor against the Decision of Pre-Trial Chamber I of 24 December 2007, ICC-01/04-503 OA4 OA5 OA6, 30 June 2008, para. 30 (‘If the Appeals Chamber were to answer such a request, it would have to assume the role of an advisory body, which it considers to be beyond and outside the scope of its authority’).

37 E.g., ‘[As] far as Mr Lubanga Dyilo's arguments regarding the purported violation of his fundamental rights are concerned, any discussion by the Appeals Chamber of the issues raised would be abstract and hypothetical. Therefore, the Appeals Chamber sees no need to address the merits of Mr Lubanga Dyilo's submissions under the second issue on appeal.’ Prosecutor v. Lubanga, Judgment on the Appeals of Mr Lubanga Dyilo and the Prosecutor against the Decision of Trial Chamber I of 14 July 2009 Entitled ‘Decision Giving Notice to the Parties and Participants that the Legal Characterisation of the Facts May Be Subject to Change in Accordance with Regulation 55(2) of the Regulations of the Court’, ICC-01/04-01/06-2205 OA15 OA16, 8 December 2009, paras. 110-111. In addition, see Prosecutor v. Lubanga, Judgment on the Prosecutor's Appeal against the Decision of Pre-Trial Chamber I Entitled ‘Decision Establishing General Principles Governing Applications to Restrict Disclosure Pursuant to Rule 81 (2) and (4) of the Rules of Procedure and Evidence’, ICC-01/04-01/06-568 OA3, 13 October 2006, para. 75; Prosecutor v. Lubanga, Judgment on the appeal of Mr Lubanga Dyilo against the Oral Decision of Trial Chamber I of 18 January 2008, ICC-01/04-01/06-1433 OA11, 11 July 2008, para. 52; Prosecutor v. Lubanga, Judgment on the appeal of Mr Thomas Lubanga Dyilo against the Decision of Pre-Trial Chamber I Entitled ‘Décision sur la demande de mise en liberté provisoire de Thomas Lubanga Dyilo’, ICC-01/04-01/06-824 OA7, 13 February 2007, paras. 122 and 138; Prosecutor v. Kony et al., Judgment on the Appeals of the Defence against the Decisions Entitled ‘Decision on Victims’ Applications for Participation a/0010/06, a/0064/06 to a/0070/06, a/0081/06, a/0082/06, a/0084/06 to a/0089/06, a/0091/06 to a/0097/06, a/0099/06, a/0100/06, a/0102/06 to a/0104/06, a/0111/06, a/0113/06 to a/0117/06, a/0120/06, a/0121/06 and a/0123/06 to a/0127/06’ of Pre-Trial Chamber II, ICC-02/04-179 OA and ICC-02/04-01/05-371 OA2, 23 February 2009, para. 38.

38 Before the Trial Chamber, the prosecution simply noted that ‘the existing practice so far of the court appears to embrace a restrictive interpretation of commencement of trial whereby only the formal opening of trial proceedings with opening statements followed by evidence constitutes the commencement of trial’. Prosecutor v. Katanga and Ngudjolo, Transcript of 1 June 2009, ICC-01/04-01/07-T-65-ENG ET, at 29, lines 5–8, and at 45, lines 15–18. On appeal, the prosecution did not address the substance of this question for the very reason that the Trial Chamber's finding did not affect the outcomes of the decision under appeal: Prosecutor v. Katanga and Ngudjolo, Prosecution's Response to Document in Support of Appeal of the Defence for Germain Katanga against the Decision of the Trial Chamber ‘Motifs de la décision orale relative à l'exception d'irrecevabilité de l'affaire’, ICC-01/04-01/07-1349, 30 July 2009 (hereinafter Prosecution Response to Katanga Admissibility Appeal), paras. 36–37. The Appeals Chamber has been cautious about ruling on questions without full argument from all relevant parties (see e.g. Ntaganda Admissibility Appeal Judgment, para. 54; although if it had considered it desirable to rule on this point, and necessary to have the views of the prosecution in order to enable it to do so, it could have requested additional submissions for this purpose under Regulation 28.

39 See, e.g., Ntaganda Admissibility Appeal Judgment, supra note 3, paras. 54, 68–82; Prosecutor v. Lubanga, Judgment on the Appeal of Mr Thomas Lubanga Dyilo against the Decision of Pre-Trial Chamber I Entitled ‘First Decision on the Prosecution Requests and Amended Requests for Redactions under Rule 81’, ICC-01/04-01/06-773 OA5, 14 December 2006, paras. 40–51; Prosecutor v. Bemba, Judgment on the appeal of the Prosecutor against Pre-Trial Chamber II's ‘Decision on the Interim Release of Jean-Pierre Bemba Gombo and Convening Hearings with the Kingdom of Belgium, the Republic of Portugal, the Republic of France, the Federal Republic of Germany, the Italian Republic, and the Republic of South Africa’, ICC-01/05-01/08-631-Red OA2, 2 December 2009, paras. 90, 104–109.

40 Katanga Admissibility Appeal Judgment, supra note 5, para. 38.

41 As noted in the Katanga admissibility proceedings and in the Katanga Admissibility Appeal Brief, Trial Chamber I held that ‘trial is considered to have begun’ on ‘the true opening of the trial when the opening statements, if any, are made prior to the calling of witnesses’. Prosecutor v. Lubanga, Decision on the Status before the Trial Chamber of the Evidence Heard by the Pre-Trial Chamber and the Decisions of the Pre-Trial Chamber in Trial Proceedings and the Manner in which Evidence shall be Submitted, 13 December 2007, ICC-01/04-01/06-1084, para. 39; as cited in Katanga Admissibility Appeal Brief, supra note 28, para. 17. The potential for uncertainty impacting on the parties in other cases is not purely hypothetical; see, e.g., the concern expressed in Prosecutor v. Bemba, Requête aux fins de divulgation des éléments pertinents relatifs á l'admissibilité, ICC-01/05-01/08-458, 22 July 2009.

42 ‘[At] the time of the admissibility challenge proceedings before the Trial Chamber, there were no proceedings in the DRC in respect of the Appellant. Hence, the question of whether the “same-conduct test” is correct is not determinative for the present appeal.’ Katanga Admissibility Appeal Judgment, supra note 5, para. 81.

43 For example, shortly before the delivery of the Katanga Admissibility Appeal Judgment the Appeals Chamber had delivered another judgment which touched on questions of admissibility (Kony Admissibility Appeal Judgment, supra note 5, paras. 69–87). In that judgment, the Appeals Chamber had upheld the initiation of a proprio motu review of admissibility by a Pre-Trial Chamber in part because the review was based on admissibility under Art. 17(1)(a) (as opposed to Art. 17(1)(d), which had been the subject of an earlier Appeal Chamber judgment: Ntaganda Admissibility Appeal Judgment, supra note 3), in addition to being conducted in public after an arrest warrant had already been issued (Kony Admissibility Appeal Judgment, supra note 3, para. 85). The second ground of appeal in Katanga's appeal thus could have provided an opportunity for the Appeals Chamber to examine how admissibility under Art. 17(1)(a) applies at the earlier stage of the issuance of an arrest warrant, but it chose not to do so.

44 The Appeals Chamber emphasized this link to its past practice in relation to the requirement that any error has materially affected the appealed decision; see Katanga Admissibility Appeal Judgment, supra note 5, para. 37.

45 Katanga lodged his appeal on 22 June 2009 (ICC-01/04-01/07-1234) and filed his appeal brief on 8 July 2009 (ICC-01/04-01/07-1279). The pleadings closed with the filing of the prosecution's consolidated response to the observations of the victims and the DRC authorities, on 7 September 2009 (ICC-01/04-01/07-1459), and the Appeal Judgment was delivered on 25 September 2009.

46 At the time that Katanga lodged his appeal, the trial was scheduled to commence on 24 September 2009 (Prosecutor v. Katanga and Ngudjolo, ICC-01/04-01/07-999, 27 March 2009). Shortly prior to the close of pleadings in the appeal, that date was postponed until 24 November 2009 (Prosecutor v. Katanga and Ngudjolo, ICC-01/04-01/07-1442, 31 August 2009).

47 Katanga Admissibility Appeal Brief, supra note 28, para. 55.

48 See, e.g., Prosecution Response to Katanga Admissibility Appeal, supra note 38, paras. 3, 51–53, 60 ff.

49 The Katanga Admissibility Appeal Judgment, supra note 5, para. 75, explains that ‘Article 17 (1) (a) of the Statute covers a scenario where, at the time of the Court's determination of the admissibility of the case, investigation or prosecution is taking place in a State having jurisdiction. This is expressed by the use of the present tense, “[t]he case is being investigated or prosecuted by a State” (emphasis added). Article 17 (1) (b) of the Statute covers a similar scenario where a State having jurisdiction has investigated a case, but “has decided not to prosecute the person concerned” (emphasis added).’

50 Situation in the Democratic Republic of the Congo, Judgment on the Prosecutor's Application for Extraordinary Review of Pre-Trial Chamber I's 31 March 2006 Decision Denying Leave to Appeal, ICC-01/04-168 OA3, 13 July 2006, para. 33; see also Prosecutor v. Katanga and Ndgudjolo, Judgment on the Appeal of Mr Germain Katanga against the Decision of Pre-Trial Chamber I Entitled ‘Decision on the Defence Request Concerning Languages’, ICC-01/04-01/07-522 OA3, 27 May 2008, para. 39; Prosecutor v. Katanga and Ngudjolo, Judgment on the Appeal against the Decision on Joinder Rendered on 10 March 2008 by the Pre-Trial Chamber in the Germain Katanga and Mathieu Ngudjolo Chui Cases, ICC-01/04-01/07-573 OA6, 9 June 2008, para. 5; Prosecutor v. Lubanga, Judgment on the Appeals of the Prosecutor and the Defence against Trial Chamber I's Decision on Victim's Participation of 18 January 2008, ICC-01/04-01/06-1432 OA9 OA10, 11 July 2008, para. 55; Prosecutor v. Lubanga, Judgment on the appeal of the Prosecutor against the Decision of Trial Chamber I Entitled ‘Decision on the Consequences of Non-disclosure of Exculpatory Materials Covered by Article 54(3)(e) Agreements and the Application to Stay the Prosecution of the Accused, together with Certain Other Issues Raised at the Status Conference on 10 June 2008’, ICC-01/04-01/06-1486 OA13, 21 October 2008, para. 40.

51 See, e.g., Ntaganda Admissibility Appeal Judgment, supra note 3, paras. 42–44, 47–48; Situation in the Democratic Republic of the Congo, Judgment on the Prosecutor's Application for Extraordinary Review of Pre-Trial Chamber I's 31 March 2006 Decision Denying Leave to Appeal, ICC-01/04-168 OA3, 13 July 2006, para. 33 (‘The Appeals Chamber shall not advert to the definition of “good faith”, save to mention that it is linked to what follows and that is the wording of the Statute’); Prosecutor v. Lubanga, Judgment on the Appeal of Mr Thomas Lubanga Dyilo against the Decision of Pre-Trial Chamber I Entitled ‘Décision sur la demande de mise en liberté provisoire de Thomas Lubanga Dyilo’, ICC-01/04-01/06-824 OA7, 13 February 2007, para. 134; see also paras. 94–97 on the context of a provision; Prosecutor v. Katanga and Ngudjolo, Judgment on the Appeal of Mr Germain Katanga against the Decision of Pre-Trial Chamber I Entitled ‘Decision on the Defence Request Concerning Languages’, ICC-01/04-01/07-522 OA3, 27 May 2008, para. 37 (holding the Pre-Trial Chamber to have erred because it ‘did not comprehensively consider the importance of the fact that the word “fully” is included in the text, and the article's full legislative history’). Exceptions to this approach have arisen where a lacuna exists in the law, where the context of other provisions necessarily requires the inclusion of a particular power which is not expressly set out, or in the light of the requirement under Art. 21(3) to read the Statute consistent with internationally recognized human rights: see, e.g., Prosecutor v. Katanga, Judgment on the appeal of the Prosecutor against the Decision of Pre-Trial Chamber I Entitled ‘First Decision on the Prosecution Request for Authorisation to Redact Witness Statements’, ICC-01/04-01/07-475 OA, 13 May 2008 (context of other provisions leading to necessary implication of a power, paras. 43–56, further supported by interpretation consistent with human rights, paras. 57–58); Prosecutor v. Lubanga, Judgment on the Appeal of Mr Thomas Lubanga Dyilo against the Decision on the Defence Challenge to the Jurisdiction of the Court Pursuant to Article 19(2)(a) of the Statute of 3 October 2006’, ICC-01/04-01/06-772 OA4, 14 December 2006 (lack of express provision to challenge jurisdiction based on abuse of process, paras. 21–24, but residual ability to stay proceeding under Article 21(3), paras. 36–39).

52 Katanga Admissibility Appeal Judgment, supra note 5, para. 78.

53 As noted above, this question was debated extensively by the parties before the Trial Chamber, although both the Trial and Appeals Chambers declined to rule on it (Katanga Admissibility Decision, supra note 1, para. 95; Katanga Admissibility Appeal Judgment, supra note 5, para. 81).

54 The Appeals Chamber examined this question directly: see Katanga Admissibility Appeal Judgment, supra note 5, paras. 76, 82–83.

55 Ibid., para. 78. Under Art. 17(1)(d), a case may be declared inadmissible if it ‘is not of sufficient gravity to justify further action by the Court’. The Appeals Chamber again referred to this additional requirement, along with Arts. 17(1)(c), 19(1), and 53, when noting that ‘depending on the circumstances of each case, [the Court] may decide not to act upon a State's relinquishment of jurisdiction in favour of the Court’. Ibid., para. 85.

56 Ibid., paras. 56, 80, 111.

57 Ibid., paras. 56, 80, 81, 97, 111.

58 Namely to review existing national proceedings and determine whether they are genuine, or whether on the other hand the ICC may still exercise its jurisdiction even in the face of the purported national proceedings. See Art. 17(2) and (3); Katanga Admissibility Appeal Judgment, supra note 5, paras. 75–78.

59 The Appeals Chamber also emphasized that Art. 17 requires an assessment of unwillingness or inability in relation to the particular case at hand (Katanga Admissibility Appeal Judgment, supra note 5, para. 76; see further Batros, supra note 3.

60 Katanga Admissibility Appeal Judgment, supra note 5, paras. 78–79, 112.

61 At least in relation to the primary question of whether the state is investigating or prosecuting under Art. 17(1)(a). Similarly, provided that the decision to close an investigation did not result from a decision not to prosecute, other motives for closing the investigation could not render the case inadmissible under Art. 17(1)(b) (Katanga Admissibility Appeal Judgment, supra note 5, paras. 82–83). Nevertheless, as noted above at note 55, the Court also referred to a number of other provisions and recalled that ‘depending on the circumstances of each case, [the Court] may decide not to act upon a Stat's relinquishment of jurisdiction in favour of the Court’ (Katanga Admissibility Appeal Judgment, supra note 5, para. 85).

62 Ibid., paras. 80, 97.

63 Katanga Admissibility Appeal Brief, supra note 28, paras. 95–100; see also paras. 62–72, 92–94.

64 Katanga Admissibility Appeal Judgment, supra note 5, para. 113.

65 Ibid., paras. 85–86.

66 See Kress, C., ‘“Self-Referrals” and “Waivers of Complementarity”: Some Considerations in Law and Policy’, (2004) 2 Journal of International Criminal Justice 944CrossRefGoogle Scholar; Schabas, W.3, ‘“Complementarity in Practice”: Some Uncomplimentary Thoughts’, (2008) 19 Criminal Law Forum 5, at 7, 12–13CrossRefGoogle Scholar.

67 Katanga Admissibility Appeal Judgment, supra note 5, para. 79, referring to the fifth paragraph of the Preamble to the Statute (and also to the fourth paragraph, ‘the most serious crimes of concern to the international community as a whole must not go unpunished’). See also para. 83 (‘the provision [Art. 17(1)(b)] must also be applied and interpreted in light of the Statute's overall purpose, as reflected in the fifth paragraph of the Preamble, namely “to put an end to impunity”.’)

68 Ibid., paras. 85–86. The Trial Chamber recognized the same duty (Katanga Admissibility Decision, supra note 1, para. 79), as has the Prosecutor (Paper on Some Policy Issues before the Office of the Prosecutor, September 2003, at 5).

69 Katanga Admissibility Appeal Judgment, supra note 5, para. 86.

70 In regard to Art. 17(1)(b), the Appeals Chamber put this in even starker terms. It highlighted the absurdity that would result if the decision of a state to close an investigation in order to transfer a case to the Court resulted in that case becoming inadmissible (on the basis that it constituted a decision not to prosecute), and both potentially competent authorities were thus precluded from exercising their jurisdiction. Katanga Admissibility Appeal Judgment, supra note 5, para. 83.

71 This statement was made in the context of the situation before the Chamber, where ‘a State makes clear its unwillingness to bring the accused to justice’. Katanga Admissibility Decision, supra note 1, para. 88.

72 ‘Whether or not a case is admissible is determined by the Court, which assesses the relevant facts against the criteria of article 17 of the Statute.’ Katanga Admissibility Appeal Judgment, supra note 5, para. 111.

73 Ibid., paras. 56, 80, 111.

74 I.e. whether or not the state is investigating or prosecuting the case; ibid., paras. 75, 78, 80. The objective nature of this primary determination is also consistent with the efforts of the states to create objective parameters for the assessment of ‘unwillingness’ or ‘inability’ when drafting Art. 17; see Holmes, supra note 2, at 673–4.

75 Such as the definitions of ‘unwillingness’ and ‘inability’ in Arts. 17(2) and (3); or the procedure in Art. 87(7) for the Court to follow in cases of non-co-operation with a request under Part 9 of the Statute.

76 Katanga Admissibility Appeal Judgment, supra note 5, para. 111.

77 Ibid., para. 86.

78 Ibid., paras. 56, 80, 111.

79 Ibid., para. 86.

80 A similar realist interpretation of the Court's relationship with states is reflected in Prosecutor v. Bemba, Judgment on the Appeal of the Prosecutor against Pre-Trial Chamber II's ‘Decision on the Interim Release of Jean-Pierre Bemba Gombo and Convening Hearings with the Kingdom of Belgium, the Republic of Portugal, the Republic of France, the Federal Republic of Germany, the Italian Republic, and the Republic of South Africa’, ICC-01/05-01/08-631-Red OA2, 2 December 2009, paras. 106–107.

81 The Trial Chamber acknowledged this implication directly; see Katanga Admissibility Decision, supra note 1, paras. 79 (‘[If] a State considers that it is more opportune for the Court to carry out an investigation or prosecution, the State will still be complying with its duties under the complementarity principle’) and 80 (‘A State may, without breaching the complementarity principle, refer a situation concerning its territory to the Court if it considers it opportune to do so, just as it may decide not to carry out an investigation or prosecution of a particular case’).

82 See in particular Katanga Admissibility Appeal Brief, supra note 28, paras. 64–66, 100.

83 Katanga Admissibility Appeal Judgment, supra note 5, para. 85.

84 Arts. 13(a) and 14(1). See A. Marchesi, ‘Article 14’, in O. Triffterer (ed.), Commentary on the Rome Statute of the International Criminal Court (2009), 575, at 579 [11]–[12]; see also Schabas, supra note 66, at 13 (‘a complainant state was being prevented from submitting a specific case or crime to the Court. It could only refer a “situation”’). For example, although Uganda sought to refer ‘the situation concerning the Lord's Resistance Army’, the Prosecutor clarified that ‘the scope of the referral encompasses all crimes committed in Northern Uganda in the context of the ongoing conflict involving the LRA’. Prosecutor v. Kony et al., Decision to Convene a Status Conference on the Investigation in the Situation in Uganda in Relation to the Application of Article 53, ICC-02/04–01/05–68, 2 December 2005, paras. 4–5.

85 Art. 53(1).

86 As the Prosecutor recognized from the outset, ‘there are limits on the number of prosecutions the ICC can bring’ (Paper on Some Policy Issues, supra note 68, at 4). According to the Draft Prosecutorial Strategy 2009–2012, 18 August 2009, the Office of the Prosecutor aims to conduct in the order of four trials, and conduct approximately 11 investigations in the period 2009–12 (at 2). In addition, that limited number of cases will be focused on the prosecution of ‘those who bear the greatest responsibility for the most serious crimes’ (ibid., at 6).

87 Such a case must by definition be serious to meet the threshold of gravity under Art. 17(1)(d) and in the light of the prosecutorial policy to prosecute ‘those who bear the greatest responsibility for the most serious crimes’. Draft Prosecutorial Strategy, supra note 86, at 6; see also Report on Prosecutorial Strategy, 14 September 2006, at 5; Paper on Some Policy Issues, supra note 68, at 3, 7.

88 See in particular Stahn, C., ‘Complementarity: A Tale of Two Notions’, (2007) 19 Criminal Law Forum 87CrossRefGoogle Scholar; Burke-White, W., ‘Implementing a Policy of Positive Complementarity in the Rome System of Justice’, (2007) 19 Criminal Law Forum 59CrossRefGoogle Scholar. This notion has also been referred to as ‘proactive complementarity’ – see Burke-White, W., ‘Proactive Complementarity: The International Criminal Court and National Courts in the Rome System of International Justice’, (2008) 49 Harvard International Law Journal 53Google Scholar. On the link between positive or proactive complementarity and the practical limitations of ICC operations, see Burke-White, ‘Implementing a Policy of Positive Complementarity’, at 66–7; J. Almqvist, ‘Complementarity and Human Rights: A Litmus Test for the International Criminal Court’, (2008) 30 Loyola of Los Angeles International and Comparative Law Review 335, at 349–50. David Tolbert, who served as both Deputy Prosecutor and Deputy Registrar at the International Criminal Tribunal for the former Yugoslavia (ICTY), also linked positive complementarity to the limitations on the workload of international courts and the practice of the ICTY of referring cases back to national jurisdictions: Tolbert, D., ‘International Criminal Law: Past and Future’, (2009) 20 University of Pennsylvania Journal of International Law 1281 at 1293–4Google Scholar; see also Kaye, D., ‘New World Order or a World in Disorder? Testing the Limits of International Law: Late-Breaking Issues and the International Criminal Tribunals – Introductory Remarks’, (2005) 99 American Society of International Law Proceedings 277Google Scholar.

89 Stahn, supra note 88, in particular at 88–9. Also referred to as ‘passive complementarity’ – see Burke-White, ‘Proactive Complementarity’, supra note 88. In relation to the classical conception of complementarity being designed primarily as a protection for the interests or sovereignty of states, see further Burke-White, ‘Implementing a Policy of Positive Complementarity’, supra note 88, at 60; Gioia, F., ‘State Sovereignty, Jurisdiction, and “Modern” International Law: The Principle of Complementarity in the International Criminal Court’, (2006) 19 Leiden Journal of International Law 1095, at 1101CrossRefGoogle Scholar; Holmes, supra note 2, at 668; S. Williams and W. Schabas, ‘Article 17’ in Triffterer, supra note 84, 605 at 606 [1], also at 613 [20].

90 Burke-White, ‘Implementing a Policy of Positive Complementarity’, supra note 88, at 66; Stahn, supra note 88, at 90 and 92; Gioia, supra note 89, at 1114; Seils, P., ‘Justice Should Be Done, but Where? The Relationship between National and International Courts’, (2007) 101 American Society of International Law Proceedings 289, at 293Google Scholar.

91 Katanga Admissibility Decision, supra note 1, para. 79; Katanga Admissibility Appeal Judgment, supra note 5, paras. 85–86.

92 See further Batros, supra note 3.

93 ‘[Admissibility] can be regarded as the tool allowing the implementation of the principle of complementarity in respect of a specific scenario.’ Kony Admissibility Decision, supra note 3, para. 34.

94 Ibid., para. 44; see further Batros, supra note 3.

95 Prosecutor v. Lubanga, Judgment on the Appeal of Mr Thomas Lubanga Dyilo against the Decision on the Defence Challenge to the Jurisdiction of the Court Pursuant to Article 19(2)(a) of the Statute of 3 October 2006, ICC-01/04-01/06-772 OA4, 14 December 2006, para. 23.

96 The Prosecutor articled a similar vision of the distinction at the Eighth Session of the Assembly of States Parties, noting that when complementarity is raised as a question of admissibility then it is a judicial matter; but positive complementarity operates in a different field and concerns the role that a range of stakeholders can play in ensuring the achievement of the goals of the Rome Statute (Luis Moreno-Ocampo, Address to the Assembly of States Parties, Opening of the Eighth Session of the Assembly of States Parties to the Rome Statute, 18 November 2009).

97 Burke-White, ‘Implementing a Policy of Positive Complementarity’, supra note 88, at 62, going on at 63–70 to examine in detail the links between the legal basis of positive complementarity and the mandate of the Office of the Prosecutor. See also Burke-White, ‘Proactive Complementarity’, supra note 88, at 76–86; C. Stahn, supra note 88, at 94–95, 105–107.

98 Seils, supra note 90, at 293, referring in particular to the monitoring and pre-investigation phases. This is further consistent with the fact that, unlike admissibility or ‘classical’ complementarity, positive complementarity is not limited in its application to specific cases.

99 While the primary responsibility for positive complementarity may lie with the Prosecutor, other organs of the Court may also play a role: see S. Arbia, ‘Discussion Paper: The Three-Year Plans and Strategies of the Registry in Respect of Complementarity for an Effective Rome Statute System of International Criminal Justice’, prepared for the Consultative Conference on International Criminal Justice, 9–11 September 2009, New York, available at www.internationalcriminaljustice.net/experience/papers/session2.pdf (last visited 17 December 2009).

100 The Prosecutor has recognized both the role that admissibility assessments must play in all phases of the proceedings (Informal Expert Paper: The Principle of Complementarity in Practice, 2003, at 9–13), and has also developed internal policies and practices regarding case selection and positive complementarity (Draft Prosecutorial Strategy, supra note 86, at 6). On the relationship between complementarity and prosecutorial discretion, see Stahn, supra note 88, at 92–3, 105–7. On the importance of prosecutorial discretion in the ICC generally, see A. Danner, ‘Enhancing the Legitimacy and Accountability of Prosecutorial Discretion at the International Criminal Court’, (2003) 97 AJIL 510, in particular at 522, 542; Brubacher, M. R., ‘Prosecutorial Discretion within the International Criminal Court’, (2004) 2 Journal of International Criminal Justice 71, in particular at 78–9CrossRefGoogle Scholar.

101 [See R. Gallmetzer ‘Prosecuting Persons Doing Business with Armed Groups in Conflict Areas – the Strategy of the OTP and the OTP's Law Enforcement Network’ in (2010) Journal of International Criminal Justice (forthcoming)] For an example of this approach in the situation in Kenya, see ‘Minutes of Meeting of 3 July 2009 between the ICC Prosecutor and the Delegation of the Kenyan Government’, 3 July 2009; ‘ICC Prosecutor: Kenya Can Be an Example to the World’, ICC-OTP-20090918-PR452, 18 September 2009; ‘ICC Prosecutor Supports Three-Pronged Approach to Justice in Kenya’, ICC-OTP-20090930-PR456, 30 September 2009, all available at www.icc-cpi.int/Menus/ICC/Structure+of+the+Court/Office+of+the+Prosecutor/Comm+and+Ref/Kenya/ (last visited 17 December 2009).