The ICC was meant to end impunity for the world’s worst crimes, thus contributing to their prevention. But twenty years after its establishment, its “theory of change” remains unclear, and few studies focus on its impact on the ground. To assess the Court’s impact, it is necessary to define the assumptions underlying its establishment. While deterrence is one such assumption, to date the evidence that the ICC effectively deters crimes is lacking. Other assumptions can be found in the Rome Statute itself, or in the expressed intentions of the Assembly of States Parties or senior officials of the Court. Lessons can also be drawn from impact studies of other international criminal tribunals. These sources indicate that the ICC should play an expressive function by engaging in norm projection. The chapter identifies four intended effects of the Rome Statute and ICC, including systemic effect on domestic legal systems; transformative effect on peace processes; reparative effect on victims; and demonstration effect, relating to its expressive function among affected communities. These four effects form an analytical framework to assess the impact of the ICC.

Chapter 4 discusses transformative effect, that is, the impact of the Rome Statute and the Court on political processes such as peace negotiations, in order to contribute to ending impunity. The chapter discusses the mechanisms of the Rome Statute that seek to balance peace and justice, including Articles 16 and 53 (the “interests of justice” test). It also discusses who determines the interests of victims in peace and justice. The evidence on whether arrest warrants facilitate or hinder peace negotiations is not conclusive, although in Uganda, they may have hindered reaching a final peace agreement. Moreover, in Afghanistan or Libya, amnesties were passed, in spite of the involvement of the ICC. The coming into force of the Rome Statute does not constitute a “paradigm shift” from impunity to accountability as such, but transformative effect may be seen in certain negotiations or peace agreements.

Chapter 5 analyses the impact of the ICC on peace negotiations in Colombia and Uganda, including impact of the ICC (and the role of the Prosecutor) on the process of negotiations, on the role of the parties, on victims, and on the content of peace agreements arising from these negotiations (including the Ugandan Agreement on Accountability and Reconciliation and the Legal Framework for Peace and Havana Peace Agreement in Colombia). The chapter concludes that there was a transformative effect in peace processes in Colombia and Uganda. These agreements adopted accountability provisions. However, they provided for alternative penalties for perpetrators rather than lengthy prison terms. They incorporated the views of victims into negotiations and allowed for various victim-oriented mechanisms in the agreements. In Uganda, however, unlike in Colombia, the final peace agreement was never fully implemented. The Colombian agreement may set new standards on how peace agreements may approach the balance between peace and justice in the future.