II. The ICC, the Rome Statute, and Principle of Complementarity

The ICC was created as a complementary court, which aims to “complement, not replace, national Courts.”6 This founding principle is highlighted in the Preamble of the Rome Statute and in Article 1.7 The principle of complementarity also guides the admissibility of cases facing the Court as outlined in Article 17 of the Rome Statute.8 Article 17 provides that a case is inadmissible where it is being:

[I]nvestigated or prosecuted by a State which has jurisdiction over it, unless the State is unwilling or unable to genuinely carry out the investigation or prosecution.9

A case is also inadmissible where a State with jurisdiction over it “has decided not to prosecute,” unless that decision results from unwillingness or inability.10 Finally, cases are inadmissible where the case is not of “sufficient gravity to justify further action.”11 Even beyond these provisions, Article 53 provides that the Prosecutor may decide to not initiate an investigation where there are “substantial reasons to believe that an investigation would not serve the interests of justice.”12 Given these bases for deciding to forgo an investigation or prosecution, the ICC Prosecutor has various options to defer to authorities besides the ICC.

Regional organizations, and particularly regional courts, can and should satisfy the requirements outlined under Article 17. There are various arguments to support this notion.

First, it has been argued that using a purposive approach to interpret the Rome Statute, considering the normative message that arises from the treaty text, the ICC is most fundamentally a court of “last resort” which maintains the primacy of state sovereignty.13 This approach provides that complementarity is meant to limit the involvement of the ICC and encourage states or regional groups of states to prosecute grave international crimes.14 Using this logic, regional courts should be respected as valid prosecutions under the principle of complementarity as long as they are genuine and effective. This approach requires regional courts and the ICC to be cooperative and provide mutual assistance as they would likely have potentially competing mandates.15

Another argument for regional complementarity arises from interpreting the Rome Statute in terms of Article 31 of the Vienna Convention on the Law of Treaties.16 This approach emphasizes interpretation in light of the object and purpose of the Rome Statute and similarly finds that complementarity is rooted in state sovereignty and a restrained role for the ICC as a “court of last resort.”17 Additionally, when criminal prosecutions reach a regional tribunal, states who are party to the tribunal typically delegate their national criminal jurisdiction to the regional tribunal.18 This type of delegation is permissible under international law and leads to the situation being genuinely investigated according to the wishes of a sovereign state.19 Using this logic, a valid prosecution by a regional tribunal should be upheld under the principle of complementarity.20

A potential difficulty in the principle of regional complementarity is that regional courts as they exist today are not empowered to prosecute individuals for international crimes, and this could conflict with the Rome Statute’s requirement of a genuine investigation or prosecution. However, the ICC has been heavily criticized for its Western emphasis on individual criminal punishment.21 Regional courts may not pursue individual prosecutions, but they have a multitude of other approaches to ensuring justice and accountability for the same grievous crimes.22 These courts primarily hear cases against states which violate human rights rather than individuals, but the benefits they reap are aligned with the goals of international justice and ending impunity for grave international crimes.23

Regional courts often focus more on policy, collaboration with civil society, and social movements in order to secure justice.24 The European Court of Human Rights has a broad range of remedies, including ordering damages and general measures to repeat recurrence of crimes such as building new detention centers and overseeing ethics commissions.25 The Inter-American Human Rights System influences domestic authorities to implement policies to account for grave international crimes and advance institutional reforms to prevent recurrence.26 These methods were even leveraged to advance national criminal prosecutions, state-sponsored truth commissions, and constitutional reforms.27

Complementarity is meant to respect the sovereignty of states who choose to carry out justice in their own systems. The value of regional courts is well-established, and in fact, it has been shown that these courts are more efficient in preventing and accounting for mass atrocities, given their budget, than the ICC.28 The ICC could benefit from a broader idea of what entails a genuine investigation or even a genuine form of justice for these grave crimes.29 Furthermore, this broader approach to accepted forms of genuine justice is permissible in the Rome Statute. Under Article 53, the Prosecutor could decide that an investigation or prosecution would not serve the interests of justice because there is already a genuine form of justice being reached through a regional court.30 There is no universal definition of what “justice” means in this context, and the ICC could benefit from a more diverse definition of international justice.31

In fact, in embracing a more comprehensive approach to complementarity, the ICC could provide space for longer-lasting, more effective forms of justice, and increase its own legitimacy in the process. Non-western, traditional, restorative, indigenous, and other justice mechanisms could be employed at various levels of international justice through a broader understanding of complementarity or in the interests of justice under Article 53.32 Trials are not the only solution to mass atrocities, and when the affected communities choose alternative justice mechanisms, whether in national courts or regional courts, the ICC should empower and encourage those communities to pursue justice in a way that is meaningful to them.33 The ICC’s limited approach to individual criminal prosecutions in the context of mass atrocities leaves many victims whose crimes are not prosecuted.34 By investing in local communities and allowing broader forms of justice to qualify as genuine justice mechanisms, the ICC could more adequately address the harms of all victims involved in crimes.

Finally, regional complementarity could also be ensured by amending the Rome Statute to explicitly include regional courts as part of the principle of complementarity. Kenya has proposed this method, but amendments to the Rome Statute are challenging and this outcome is unlikely.35

III. Framing Proactive Regional Complementarity

Literature has attempted to frame the principle of complementarity in a variety of ways from positive complementarity to radical complementarity to proactive complementarity.36 This comment combines aspects of Burke-White’s “proactive complementarity” and Sarah Nimigan’s conception of “regional complementarity” to frame a potential relationship between the ICC and regional courts.37

This proposed conception of regional complementarity emphasizes not only that regional courts can satisfy complementarity, but that the relationship should be based on cooperation at national, regional, and international levels.38 Mutual assistance between courts at all levels would build capacity for various institutions that can become stronger players in international justice. This will also alleviate some of the burden off of the ICC so that justice can be pursued in a broader range of forums, each with unique strengths. This is similar to proactive complementarity in that the ICC could participate more directly to encourage prosecution of international crimes, particularly through collaboration and mutual assistance, such as the exchange of evidence.39

A key component of this form of regional complementarity is its encouragement of a more fruitful distribution of prosecutorial roles. Nimigan suggests that ideally, national jurisdictions would investigate and prosecute foot soldiers, regional jurisdictions would pursue rebel leaders, military commanders or intermediaries, and the ICC would prosecute heads of state and government officials.40

There are a multitude of benefits to this distribution of power, foremost being a more holistic approach to criminal justice. There are jurisdictional benefits in that the ICC would primarily be tasked with heads of state and high-level officials, who don’t receive immunity at the ICC.41 Additionally, these roles serve the interests of capacity for these differing institutions, as the distribution of caseload would free up the ICC to focus on the most culpable. Meanwhile, regional and national courts could deal with larger caseloads of lower-profile cases.

This arrangement also serves the benefits of justice as national jurisdictions would focus on foot soldiers, who typically commit the most direct and localized forms of violence perpetrated against victims.42 The ability to gather evidence on the ground would be substantially easier for domestic jurisdictions, and victims would be able to face their perpetrators. This in turn would create greater prospects for transition and stability following mass atrocity.43 Spreading the potential avenues of justice could also help counter accusations of bias against the ICC.

This notion of complementarity is “more relational than vertical/hierarchical” as each judicial mechanism is interdependent and strengthens the other if effective coordination is implemented.44 International, regional, and national systems would share a commitment to cooperative international criminal justice rather than any having primacy over the other. This comment proposes that these roles can expand beyond the narrow definitions of investigation and prosecution and encompass more broad definitions of pursuing justice.45 As regional courts and organizations encompass a broader approach to ensuring international criminal justice than just individual prosecution, proactive regional complementarity should allow for different justice methods to serve the requirement of a genuine proceeding.

IV. The Inter-American Human Rights System

The Inter-American Human Rights System, encompassing both the Inter-American Court and the Inter-American Commission on Human Rights, provides a valuable example of the broader definitions of justice that could fit into proactive regional complementarity.

The Inter-American System has been described as quasi-criminal, as it holds states accountable for crimes despite not officially being a criminal court.46 The Inter-American Court is uniquely skilled at leveraging its competencies to advance state prosecutions.47 The Court also monitors states’ implementations of its orders through mandatory hearings and compliance reports.48 However, beyond these functions, the Inter-American Court also advances truth commissions, reparations programs, sites of historical memory, and various measures to facilitate truth-telling, accountability, and the prevention of mass atrocities.49

The Inter-American Commission for Human Rights is more deferential to states, but fosters local processes of justice.50 The rights body entrusts local justice systems with retributive justice, while also maintaining restorative justice and victim-centered remedies.51 In this way, the Inter-American Human Rights System presents a more cohesive approach to justice, with a greater emphasis on justice for victims and repairing the social fabric of communities following mass atrocities. The ICC could learn from this approach, as its focus on individual criminal responsibility does little to repair the damage done to entire communities in conflict zones.

The efficacy of this system is evidenced by the impacts of the Inter-American Court as compared to the ICC. Regional tribunals have been more effective than international criminal tribunals in securing accountability for mass atrocities.52 In fact, the sentences influenced by the Inter-American Court have been nearly as significant as the ICC, the International Criminal Tribunal for the former Yugoslavia and the International Criminal Tribunal for Rwanda combined.53 Pursuant to Court decrees, states have:

[L]aunched new criminal investigations, exhumed mass graves, moved cases from military to civil jurisdiction, overturned amnesties, bypassed statutes of limitations, and created new institutions and working methods.54

This is particularly poignant, given that the ICC’s budget vastly exceeds those of all regional institutions, and the ICC cost about thirty-three times as much as the Inter-American Court between 2011 and 2018.55

Regional courts such as the Inter-American Court are partially more cost-effective because they are more closely connected to the surrounding states they serve.56 Local investigators and prosecutors may speak the necessary languages and understand the complex contexts of the surrounding communities’ culture, politics, and social fabric.57 This connection to the region accumulates less financial burden than the ICC faces in hiring experts, but it also creates a more accurate perception of how atrocities occurred given the particular unique contexts of the territory they occurred in. This also combats much of the criticism the ICC faces in imposing Western ideals of justice on societies with different approaches to criminal justice.

The ICC’s role in Colombia’s peace negotiations is evidence of the potential benefits of a broader, more collaborative approach to regional complementarity. The ICC kept the Court’s examination of Colombia in the preliminary investigation stage for years and regularly engaged in public and private peace talks with the Colombian government, judiciary, and civil society.58 This flexible, collaborative approach allowed the possibility of a peace agreement and potential criminal prosecutions in Colombian courts, even with the continuous participation of the ICC. The ICC closed its investigation and signed an agreement with Colombia to continue engaging through exchanging lessons learned and best practices, which is precisely in line with the mutual assistance found in regional complementarity.59

The Inter-American Court has been most effective in understanding its limitations and contributing to locally driven efforts.60 This institution was designed to complement national political and legal systems, with domestic actors being primarily responsible for preventing human rights violations.61 In a similar vein, the ICC would substantially benefit from recognizing its own limitations and delegating more substantially to regional efforts. The ICC was founded on the principle of complementarity, but in practice, it has not engaged in proactive complementarity to truly foster regional and national jurisdictions achieving justice on their own terms. Instead, the ICC has viewed itself as a primary agent of international justice.62 More intentional collaboration across varying institutions could achieve mutual benefits which inspire more effective, long-lasting international justice.

V. Conclusion

There is great potential in a more collaborative approach to proactive regional complementarity. In the interest of creating more formal cooperative relations, the ICC could negotiate and develop agreements between the Court and various regional organizations to share prosecutorial responsibilities in certain ways. With a broad interpretation of the acceptable forms of justice under the principle of complementarity, the Court could create a more just and effective distribution of responsibilities in approaching cases of grave international human rights violations. A formalized agreement would help achieve the ideal distribution of roles discussed earlier and facilitate concrete collaboration, such as through the provision of evidence from one justice mechanism to another. The potential for collaboration with parties outside of traditional justice mechanisms, from civil society to NGOs, would also be incredibly beneficial to the ICC and regional courts alike.

The field of international justice is complex and challenging, and the more the ICC is willing to recognize the unique skills and contexts of different players in the global system, the easier it will be for the Court to refocus its resources towards fulfilling its own mandate. When national, regional, and international institutions and actors each take responsibility for pursuing justice and fighting against global impunity, the field of international justice will continue to grow, with increasing intersectionality, and advance the protection of human rights around the world.

Endnotes — (click the footnote reference number, or ↩ symbol, to return to location in text).

1. 1.

   About the Court, ICC, available online (last visited Aug. 29, 2023). ↩

2. 2.

   Has the ICC Under-Represented Non-Western Legal Traditions?, ICC Forum (Jul. 25, 2022) [hereinafter Under-Represented Legal Traditions], available online; Is the ICC Targeting Africa Inappropriately?, ICC Forum (Mar. 17, 2013), available online. ↩

3. 3.

   About the Court, supra note 1. ↩

4. 4.

   Rome Statute of the International Criminal Court, Adopted by the United Nations Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, Jul. 17, 1998, U.N. Doc. A/CONF.183/9 [hereinafter Rome Statute], Art. 17, available online. ↩

5. 5.

   Sarah P. Nimigan, The Malabo Protocol, the ICC, and the Idea of “Regional Complementarity”, 17 J. Int’l Crim. Just. 1005 (Nov. 5, 2019), paywall, earlier version, doi. ↩

6. 6.

   About the Court, supra note 1. ↩

7. 7.

   Rome Statute, supra note 4, at Art. 1. ↩

8. 8.

   Id. Art. 17. ↩

9. 9.

   Id. ↩

10. 10.

    Id. ↩

11. 11.

    Id. ↩

12. 12.

    Id. Art. 53. ↩

13. 13.

    Nimigan, supra note 5, at 1020. ↩

14. 14.

    Id. ↩

15. 15.

    Id. at 1022. ↩

16. 16.

    Miles Jackson, Regional Complementarity: Rome Statute and Public International Law, 14 J. Int’l Crim. Just. 1061 (Dec. 17, 2016), available online, doi; Vienna Convention on the Law of Treaties, Art. 31, May 23, 1969, 1155 U.N.T.S. 331, available online, archived. ↩

17. 17.

    Jackson, supra note 16. ↩

18. 18.

    Id. ↩

19. 19.

    Id. at 1066. ↩

20. 20.

    Id. ↩

21. 21.

    Under-Represented Legal Traditions, supra note 2. ↩

22. 22.

    James L. Cavallaro & Jamie O’Connell, The ICC’s Best Bet: Look to Regional Systems, ICC Forum (Jul. 25, 2022), available online. ↩

23. 23.

    James L. Cavallaro & Jamie O’Connell, When Prosecution is Not Enough: How the International Criminal Court Can Prevent Atrocity and Advance Accountability by Emulating Regional Human Rights Institutions, 45 Yale J. Int’l L. 1 (2020), available online. ↩

24. 24.

    Cavallaro & O’Connell, supra note 22. ↩

25. 25.

    Cavallaro & O’Connell, supra note 23, at 32. ↩

26. 26.

    Id. ↩

27. 27.

    Id. ↩

28. 28.

    Cavallaro & O’Connell, supra note 22. ↩

29. 29.

    Darryl Robinson, Serving the Interests of Justice: Amnesties, Truth Commissions, and the International Criminal Court, 14 EJIL 481 (2003), available online. ↩

30. 30.

    Rome Statute, supra note 4, at Art. 53. ↩

31. 31.

    Ray Nickson, By Recognizing Broader, Deeper, and Longer Conceptions of Justice Through Complementarity, the ICC Can Transcend a Narrow, Western Approach to International Criminal Justice, ICC Forum (Jul. 25, 2022), available online. ↩

32. 32.

    Id. ↩

33. 33.

    Id. ↩

34. 34.

    Id. ↩

35. 35.

    African Union, Withdrawal Strategy Document, Draft 2 (Jan. 12, 2017), available online. ↩

36. 36.

    William W. Burke-White, Proactive Complementarity: The International Criminal Court and National Courts in the Rome System of Justice, 49 Harv. Int’l L.J. 53 (2008), available online. ↩

37. 37.

    Id.; Nimigan, supra note 5. ↩

38. 38.

    Nimigan, supra note 5. ↩

39. 39.

    Burke-White, supra note 36. ↩

40. 40.

    Nimigan, supra note 5, at 1022. ↩

41. 41.

    Rome Statute, supra note 4, at Art. 27. ↩

42. 42.

    Nimigan, supra note 5, at 1022. ↩

43. 43.

    Id. ↩

44. 44.

    Id. at 1026. ↩

45. 45.

    Nickson, supra note 31. ↩

46. 46.

    Alexandra Valeria Huneeus, International Criminal Law by Other Means: The Quasi-Criminal Jurisdiction of the Human Rights Courts, 107 Am. J. Int’l L. 1 (Jan. 9, 2013), available online. ↩

47. 47.

    Id. ↩

48. 48.

    Id. ↩

49. 49.

    Cavallaro & O’Connell, supra note 22. ↩

50. 50.

    Huneeus, supra note 46, at 4. ↩

51. 51.

    Id. ↩

52. 52.

    Cavallaro & O’Connell, supra note 23. ↩

53. 53.

    Id. at 46. ↩

54. 54.

    Huneeus, supra note 46, at 3. ↩

55. 55.

    Cavallaro & O’Connell, supra note 23, at 59. ↩

56. 56.

    Id. at 61. ↩

57. 57.

    Id. ↩

58. 58.

    Cavallaro & O’Connell, supra note 22. ↩

59. 59.

    Id.; Cooperation Agreement Between the Office of the Prosecutor of the International Criminal Court and the Government of Colombia, Art. 4 (Oct. 28, 2021), available online. ↩

60. 60.

    Cavallaro & O’Connell, supra note 23, at 58. ↩

61. 61.

    Id. ↩

62. 62.

    Id. at 61. ↩