In May, 36 countries and the European Union formalized an agreement in Chisinau, Moldova, establishing the Special Tribunal for the Crime of Aggression Against Ukraine. This tribunal is the product of years of diplomatic efforts initiated shortly after Russia launched its full-scale invasion of Ukraine in 2022. It aims to hold accountable those responsible for authorizing the conflict, addressing a significant gap in international justice that has persisted since World War II.

Unlike previous post-war tribunals at Nuremberg and Tokyo, which prosecuted war crimes but did not directly address the legality of initiating conflict, this new tribunal seeks to set a precedent that aggression itself is a prosecutable offense under international law. Its creation responds directly to the ongoing war in Ukraine, but officials involved emphasize its broader geopolitical implications to deter future acts of aggression globally.

Although the International Criminal Court (ICC) has already issued arrest warrants for Russian President Vladimir Putin and several top military officials for war crimes and crimes against humanity, Russia—and other major powers such as the United States, China, India, and Israel—are not ICC members. This reduces the likelihood of enforcement through extradition. However, proponents argue that sustaining and expanding such legal frameworks strengthens the global system of accountability.

Critics often point to the slow pace of international justice, the perceived selectivity in prosecution, and the failure to secure arrests as limitations that can render legal actions symbolic rather than effective. Despite these concerns, advocates maintain that continuing to build these mechanisms is vital to establishing international norms and preventing unchecked use of force. They contend that incremental progress narrows the space where powerful actors can act with impunity.

Historical precedents underscore this point. The failure to hold Russia accountable following its 2008 actions in Georgia contributed to its 2014 annexation of Crimea and the subsequent conflict in eastern Ukraine. Advocates argue that enduring impunity encourages repeated aggression. They stress that any viable cease-fire or peace agreement for Ukraine must include accountability measures—elements notably absent from current negotiations.

The experience of the Bosnian War illustrates the risks of separating justice from peace processes. Key figures indicted for war crimes were excluded from early peace talks, resulting in delays of more than a decade before arrests, which allowed nationalist revisionism to gain traction. Proponents of the tribunal argue that integrating accountability from the outset is essential to durable conflict resolution.

Although the tribunal’s establishment required compromises and has not garnered unanimous support—only a fraction of the United Nations membership signed the pact—it represents a concrete step toward challenging the notion that conquest can proceed without consequence. The tribunal’s backers assert that its mandate extends beyond Ukraine, signaling a commitment to uphold the international legal order and deter future violations worldwide.

In framing the tribunal’s significance, officials recall Robert Jackson, the chief U.S. prosecutor at the Nuremberg trials, who emphasized that the judgments rendered would shape how history judges both perpetrators and those who stand by. The choices nations make today—whether to participate in this tribunal or opt out—will form part of the historical record that future generations consult when evaluating the resilience of the post-World War II international system.