Why Ukraine’s Victory Matters for International Law

Russia’s war against Ukraine tests the global legal system, and Ukraine’s triumph could restore faith in the principles of sovereignty and collective security

The Russo-Ukrainian war has become the greatest challenge to international law since World War II. The aggression, accompanied by widespread war crimes, violations of sovereignty, and disregard for the UN Charter, has called into question the very effectiveness of the global legal system. If the aggressor remains unpunished, international law will definitively lose its effectiveness, and the world will revert to a logic of “might over right.” This is why Ukraine’s victory is critically important not only for its people but for the entire architecture of international security.

The War in Ukraine: A Precedent Shaping the 21st Century

The UN Charter and the Geneva Conventions were created to prevent the recurrence of the tragedies of world wars. However, Russia’s invasion of Ukraine has demonstrated that even a nuclear state and member of the UN Security Council can grossly violate all rules and evade accountability. This creates a dangerous precedent: if the aggression is not stopped, other authoritarian regimes may adopt a similar model of behavior. The threat looms everywhere, from Taiwan to the Balkans and Africa – the world risks facing a cascade of “small wars” if international law becomes a fiction.

Punishment and Impunity: The Consequences for the Global System Will Be Severe

Russia has already twice used its veto power in the UN Security Council to block resolutions against its own aggression. This has proven that existing international security mechanisms are vulnerable when aggressor states have institutional tools to shield themselves from punishment. If the world fails to find a way to hold Moscow accountable – through a special tribunal, reparations mechanisms, or isolation in global markets – the collective security system will lose all meaning.

In the 20th century, the Nuremberg Tribunal became a symbol that even the highest officials cannot escape justice. In the 21st century, Ukraine’s victory must pave the way for a new format of international justice. This is not only a matter of historical justice but also a fundamental test: is international law truly universal, or does it only apply to the weaker?

Ukraine’s Initiative for an International Tribunal for the Crime of Aggression Can Strengthen the Global Legal System

One of the key elements of Ukrainian diplomacy has been the promotion of the idea of a special international tribunal for the crime of aggression by the Russian Federation. The initiative has been supported by the EU, the Council of Europe, and a number of Ukraine’s partners. In 2023, the International Centre for the Prosecution of the Crime of Aggression against Ukraine (ICPA) was established in The Hague under Eurojust. It is tasked with collecting evidence and preparing future indictments for the special tribunal. In 2024–2025, over 40 countries officially declared their readiness to support the tribunal’s format – either as a standalone international institution or as a hybrid court under the auspices of the Council of Europe.

Progress is evident: there is already an agreement that the tribunal will have a mandate to address the crime of aggression by Russia’s top political leadership. This is fundamentally important because the International Criminal Court (ICC) has jurisdiction over war crimes, crimes against humanity, and genocide but cannot prosecute the crime of aggression without a UN Security Council decision – where Russia holds veto power. Ukraine’s initiative offers a way to bypass this trap. A tribunal for aggression could become the first real instrument of international law capable of holding the leadership of a nuclear state accountable.

International Experience in Punishing War Criminals and Aggressor States Offers Hope

History provides examples of the international community successfully creating effective mechanisms to punish war criminals and states that violate international law. The most notable precedent is the Nuremberg Trials after World War II, when the leaders of the Third Reich were convicted for crimes against peace and humanity. In the 1990s, the international community established special tribunals for the former Yugoslavia (ICTY) and Rwanda (ICTR), which proved that even during armed conflicts, it is possible to gather evidence, arrest, and convict those responsible for mass atrocities.

Today, the International Criminal Court continues this practice: in 2023, it issued an arrest warrant for Vladimir Putin for the deportation of Ukrainian children. This confirmed that even the highest officials are not immune to international law. These examples demonstrate that punishment is possible when there is political will and a mechanism for justice. For Ukraine, it is crucial to leverage this experience to ensure Russian criminals are held accountable not only for war crimes but also for the act of aggression itself.

Ukraine’s Victory Can Restore Trust in International Norms

If Ukraine prevails, it will serve as proof that international law has force. The world will gain a precedent where an aggressor is defeated, and the victim receives justice. This will restore trust in the principles of sovereignty, territorial integrity, and the non-use of force. For the EU, the US, and all partners, this will mean that their investments in international institutions have real value.

Moreover, Ukraine’s victory will strengthen the legitimacy of international sanctions, which are often criticized as “ineffective.” It will demonstrate that systemic economic pressure, combined with military support, can force an aggressor to retreat.

Why the War in Ukraine Is Not a Local Conflict but a Global Test

It would be a mistake to view Russia’s war against Ukraine as merely a regional conflict. In reality, it is shaping the contours of the global order for decades to come. The fact that Ukraine endures will serve as a signal to all potential aggressors: international law is protected, and collective security works. If the aggressor escapes punishment, no country in the world will feel safe.

Ukraine’s victory is not only about restoring borders but also about preserving the rules on which modern civilization is built. That is why the war in Ukraine today is a battle not only for Kyiv or Kharkiv but also for the future of international law.

Bohdan Popov, Head of Digital at the United Ukraine Think Tank, communications specialist and public figure