1 See also OTP, Prosecutorial Strategy (2009–2012), 21 December 2009, paras. 81 – 82.

2 See Election of the Prosecutor, Statement by Mr Luis Moreno-Ocampo, New York, 22 April 2003, ICC-OTP-20030502–10. See also the restatement in OTP, supra note 1, para. 81 (‘[T]he number of cases that reach the Court is not a decisive measure of effectiveness. Genuine investigations and prosecutions of serious crimes at the national level will illustrate the successful functioning of the Rome system’).

3 See OTP, Informal Expert Paper, ‘The Principle of Complementarity in Practice’, 2003; OTP, Paper on Some Policy Issues before the Office of the Prosecutor, 2003.

4 See J. Holmes, ‘Complementarity: National Courts versus the ICC’, in A. Cassese, P. Gaeta, and J. Jones (eds.), The Rome Statute of the International Criminal Court, Vol. 1 (2002), 667, at 668. For an in-depth treatment of complementarity, see J. K. Kleffner, Complementarity in the Rome Statute and National Criminal Jurisdictions (2008); M. El Zeidy, The Principle of Complementarity in International Criminal Law (2008).

5 In particular, the ICC Prosecutor has placed strong emphasis on the idea of dialogue and partnership with domestic jurisdictions. See OTP, Report on the Activities Performed during the First Three Years (June 2003–June 2006), 12 September 2006, paras. 2 and 58.

6 For a survey of the traditional understanding see F. Gioia, ‘State Sovereignty, Jurisdiction and “Modern” International Law: The Principle of Complementarity in the International Criminal Court’, (2006) 19 LJIL 1095.

7 See e.g. Burke-White, W., ‘Implementing a Policy of Positive Complementarity in the Rome System of Justice’, (2008) 19 Criminal Law Forum 5CrossRefGoogle Scholar; Stahn, C., ‘Complementarity: A Tale of Two Notions’, (2008) 19 Criminal Law Forum 87CrossRefGoogle Scholar.

8 In its Prosecutorial Strategy the OTP distinguishes ‘complementarity as an admissibility test, i.e. how to assess the existence of national proceedings and their genuineness’, and the ‘positive complementarity concept, i.e. how to promote national proceedings’. See OTP, supra note 1, para. 16. ‘Positive complementarity’ shares some of the following features: (i) it is focused on the idea of burden-sharing between the Court and national jurisdictions: the Court and domestic jurisdictions have a ‘shared responsibility’; (ii) ‘positive complementarity’ involves co-ordination and dialogue between the Court and states, in addition to vertical powers (i.e. monitoring and control of domestic jurisdiction); (iii) under ‘positive complementarity’, the decision about the forum for justice is not made exclusively on the basis of domestic ‘failure’, but may take into account the comparative advantages of the respective fora; and (iv) ‘positive complementarity’ is not only designed to preserve the primacy of domestic jurisdiction, but also to create incentives and opportunities for states to undertake genuine investigations and prosecutions.

9 See the Discussion Paper submitted by Denmark and South Africa, ‘Bridging the Impunity Gap through Positive Complementarity’, November 2009, para. 24 (‘Positive complementarity must never be an excuse for delaying or obstructing justice or become a tool in the hands of those who wish to preserve impunity, nor can it in any way affect the powers vested in the organs of the Court’).

10 See OTP, supra note 1, para. 16.

11 See Consultative Conference on International Criminal Justice, ‘The Three-Year Plans and Strategies of the Registry in Respect of Complementarity for an Effective Rome Statute System of International Criminal Justice’, discussion paper by Silvana Arbia, Registrar of the International Criminal Court, New York, September 2009.

12 The OTP has addressed some of the criteria in its 2006 Draft Paper on the selection of situations and cases.

13 PTC I has ruled since 2006 that ‘[i]t is a conditio sine qua non for a case to be inadmissible that national proceedings encompass both the person and the conduct which is the subject of the case before the Court’. See PTC I, Prosecutor v. Thomas Lubanga Dyilo, Decision on the Prosecutor's Application for Warrant of Arrest, Article 58, ICC-01/04–01/06 (10 February 2006), para. 31.

14 Ibid., para. 29.

15 See OTP, Informal Expert Paper, supra note 3, paras. 18 and 19 (‘Where no State has initiated any investigation (the inaction scenario) . . . none of the alternatives of Articles 17(1)(a)–(c) are satisfied and there is no impediment to admissibility. Thus, there is no need to examine the factors of unwillingness or inability; the case is simply admissible under the clear terms of Article 17 . . . [I]t is only where a State is investigating or prosecuting, or has already completed such a proceeding, that Article 17(1)(a)–(c) are engaged. In such circumstances, the case will be inadmissible, unless the exceptions in those provisions are established’).

16 See Prosecutor v. Thomas Lubanga Dyilo, supra note 13, para. 29 (‘The Chamber considers that the admissibility test of a case arising from the investigation of a situation has two parts. The first part of the test relates to national investigations, prosecutions and trials concerning the case at hand insofar as such case would be admissible only if those States with jurisdiction over it have remained inactive in relation to that case or are unwilling or unable, within the meaning of article 17 (1) (a) to (c), 2 and 3 of the Statute. The second part of the test refers to the gravity threshold which any case must meet to be admissible before the Court. Accordingly, the Chamber will treat them separately’).

17 See Prosecutor v. Thomas Lubanga Dyilo, supra note 13, para. 36. For a survey, see M. El Zeidy, ‘Some Remarks on the Question of the Admissibility of a Case during Arrest Warrant Proceedings before the International Criminal Court,’ (2006) 19 LJIL 741; El Zeidy, supra note 4, at 228–32.

18 See PTC I, Prosecutor v. Mathieu Ngudjolo Chio, Warrant of Arrest for Mathieu Ngudjolo Chui, unsealed on 7 February 2008.

19 See PTC II, Prosecutor v. Joseph Kony et al., Warrant of Arrest for Joseph Kony Issued on 8 July 2005 as Amended on 27 September 2005 (‘Noting the statements in the ‘Letter of Jurisdiction’ dated the 28th day of May 2004, that “the Government of Uganda has been unable to arrest . . . persons who may bear the greatest responsibility” for the crimes within the referred situation; that “the ICC is the most appropriate and effective forum for the investigation and prosecution of those bearing the greatest responsibility” for those crimes; and that the Government of Uganda “has not conducted and does not intend to conduct national proceedings in relation to the persons most responsible”; Being satisfied that, on the basis of the application, the evidence and other information submitted by the Prosecutor, and without prejudice to subsequent determination, the case against . . . falls within the jurisdiction of the Court and appears to be admissible’ (emphasis added).

20 See Appeals Chamber, Situation in Democratic Republic of the Congo, Judgment on the Prosecutor's Appeal against the Decision of the Pre-Trial Chamber Entitled ‘Decision on the Prosecutor's Application for Warrants of Arrest, Article 58’, ICC-01/04–169 (issued under seal 13 July 2006, reclassified as public on 23 September 2008, para. 52 (‘The Appeals Chamber accepts that the Pre-Trial Chamber may on its own motion address admissibility. However, in the Appeals Chamber's view, when deciding on an application for a warrant of arrest in ex parte Prosecutor only proceedings the Pre-Trial Chamber should exercise its discretion only when it is appropriate in the circumstances of the case, bearing in mind the interests of the suspect. Such circumstances may include instances where a case is based on the establishment jurisprudence of the Court, uncontested facts that render a case clearly inadmissible or an ostensible cause impelling the exercise of proprio motu review. In these circumstances it is also imperative that the exercise of this discretion take place bearing in mind the rights of other participants’).

21 See generally Kress, C., ‘“Self-referrals” and “Waivers of Complementarity” – Some Considerations in Law and Policy’, (2004) 2 Journal of International Criminal Justice 944CrossRefGoogle Scholar; J. K. Kleffner, ‘Auto-referrals and the Complementary Nature of the ICC’, in C. Stahn and G. Sluiter (eds.), The Emerging Practice of the International Criminal Court (2009), 41.

22 See Informal Expert Paper, supra note 3, para. 14 (‘There is a potential danger that if the OTP gets too closely involved in providing training, advice and assistance to a national proceeding, it may be difficult to extricate the OTP to credibly criticize and question the process if it subsequently proves to be a non-genuine proceeding . . . It is suggested that, consistent with the presumption of bona fides toward co-operative States, the OTP proceed with a positive, co-operative approach to assisting national efforts, where appropriate, albeit with some caution to avoid being exploited in efforts to legitimize or shield inadequate national efforts from criticism. The OTP can assess this approach over time in the light of experience and lessons learned’).

23 For a critical assessment, see Kleffner, supra note 4, at 222–3.

24 See Prosecutor v. Thomas Lubanga Dyilo, supra note 13, para. 35 (‘In the Chamber's view . . . it appears that the DRC was indeed unable to undertake the investigation and prosecution of the crimes falling within the jurisdiction of the Court committed in the situation in the territory of DRC since 1 July 2002. In the Chamber's view, this is why the self-referral of the DRC appears consistent with the ultimate purpose of the complementarity regime’) (emphasis added).

25 See PTC II, Decision on the Admissibility of the Case under Article 19(1) of the Statute, ICC-02/04–01/05–377 (10 March 2009), para. 45 (‘it is for the latter and not for any national judicial authorities to interpret and apply the provisions governing the complementarity regime and to make a binding determination on the admissibility of a given case’); para. 46 (‘Since admissibility is the criterion allowing the Court to identify which cases, among those in respect of which it has jurisdiction concurrently with one or more national judicial systems, it is appropriate for it to investigate and prosecute under the complementarity regime, it is the view of the Chamber that it is for it to construe and apply the rules on admissibility as well’).

26 See ICC, Prosecutor v. Germain Katanga and Mathieu Ngudjolo Chui, Motion Challenging the Admissibility of the Case by the Defence of Germain Katanga, pursuant to Article 19(2) of the Statute, 11 March 2009, paras. 16 f. The defence advocated a ‘comparative gravity’ test, which would ‘compare’ ‘the gravity of the (intended) scope of investigations at the national level and the (intended) scope of investigations by the ICC Prosecutor’, and a ‘comprehensive conduct’ test which would enable the comparison of the factual scope of the investigations.

27 See Trial Chamber I, Prosecutor v. Germain Katanga and Mathieu Ngudjolo Chui, Reasons for the Oral Decision on the Motion Challenging the Admissibility of the Case (Article 19 of the Statute), 16 June 2009, para. 77.

28 See Trial Chamber I, supra note 26, para. 49: ‘(1) During the first phase, which runs until the decision on the confirmation of charges is filed with the Registry, all types of challenges to admissibility are permissible, subject to the requirement, for States, to make them at the “earliest opportunity”. (2) In the second phase, which is fairly short, running from the filing of the decision on the confirmation of charges to the constitution of the Trial Chamber, challenges may still be made if based on the ne bis in idem principle. (3) In the third phase, in other words, as soon as the chamber is constituted, challenges to admissibility (based only on the ne bis in idem principle) are permissible only in exceptional circumstances and with leave of the Trial Chamber.’

29 See Appeals Chamber, Judgment on the Appeal of Mr Katanga against the Trial Decision of Trial Chamber II of 12 June 2009 on the Admissibility of the Case, 25 September 2009.

30 Note, however, the caution of the Appeals Chamber vis-à-vis the approach of the Trial Chamber: ‘The Appeals Chamber nevertheless wishes to stress that the fact that the Appeals Chamber is refraining from pronouncing itself on the merits of the issue raised under the first ground of appeal does not necessarily mean that it agrees with the Trial Chamber's interpretation of the term “commencement of the trial” in article 19 (4) of the Statute’. See Appeals Chamber, supra note 29, para. 38.

31 See Appeals Chamber, supra note 29, para. 78.

32 The reference of ‘primacy of domestic proceedings’ is misleading in this context, since there is no admissibility conflict, and thus no real (need for) primacy in case of inaction (the Court is then not a ‘Court of last resort’, but simply the only point of entry).

33 See Holmes, supra note 4, at 684. See also PTC II, supra note 25, para. 34 (‘Complementarity is the principle reconciling the States’ persisting duty to exercise jurisdiction over international crimes with the establishment of a permanent international criminal court having competence over the same crimes’).

34 Appeals Chamber, supra note 29, para. 56 (‘Generally speaking, the admissibility of a case must be determined on the basis of the facts as they exist at the time of the proceedings concerning the admissibility challenge. This is because the admissibility of a case under article 17(1)(a), (b) and (c) of the Statute depends primarily on the investigative and prosecutorial activities of States having jurisdiction. These activities may change over time’).

35 Ibid., para. 79.

36 See, e.g., S. A. Williams and W. Schabas, ‘On Article 17’, in O. Triffterer (ed.), Commentary on the Rome Statute of the International Criminal Court (2008), 614–16, paras. 23–24; M. H. Arsanjani and W. M. Reisman, ‘Law-in-Action of the International Criminal Court’, (2005) 99 AJIL 385.

37 See OTP, Paper on Some Policy Issues, supra note 3, at 4 (‘The principle of complementarity represents the express will of States Parties to create an institution that is global in scope while recognising the primary responsibility of States themselves to exercise criminal jurisdiction. The principle is also based on considerations of efficiency and effectiveness since States will generally have the best access to evidence and witnesses’).

38 See Appeals Chamber, supra note 29, para. 85.

39 Ibid., 169 (‘Note, however, that not every inaction of States will automatically lead to proceedings before the Court’).