International Arbitration Tribunal Delivers Landmark Ruling
On April 22, 2026, the International Arbitration Tribunal issued its decision in the case of Ukraine versus the Russian Federation, confirming that the Sea of Azov and the Kerch Strait are internal waters shared by both nations—not a Russian lake. The Permanent Court of Arbitration in The Hague published the full ruling on June 15, in which the tribunal unanimously determined that these waters do not constitute a historic bay of Russia. This internal water status aligns with the 2003 bilateral agreement on cooperation in the Azov-Kerch maritime area. Ukraine retains its standing as a coastal state in the Black Sea, the Sea of Azov, and the Kerch Strait.
Violations Found and Implications of the Verdict
The tribunal also found Russia in violation for constructing the Kerch Bridge, laying underwater power cables, and installing a gas pipeline. According to the ruling, Russia failed to conduct a proper environmental impact assessment, did not gather sufficient baseline data, and neglected to publish its evaluation results. The court determined that the obligation to cooperate on marine environmental protection had been breached. However, most of Ukraine’s other claims—concerning:
- obstruction of navigation,
- seizure of drilling platforms,
- protection of underwater cultural heritage
were dismissed due to jurisdictional limitations.
Kyiv initiated the case on September 16, 2016, and in February 2020, the arbitration tribunal in The Hague confirmed its jurisdiction to hear the dispute. Ukraine’s Ministry of Foreign Affairs stated that
“the tribunal’s ruling is further proof that Russia ignores the norms of international law.”The ministry added that
“attempts to present the consequences of aggression as a new reality will not gain international legal recognition.”In contrast, Russia’s foreign ministry claimed a 'victory for the Russian Federation in international arbitration.'
This decision carries significant weight for regional international relations, as it reaffirms Ukraine’s legal basis for control over the Sea of Azov and the Kerch Strait. The recognition of internal water status could influence future trade and security matters between Ukraine and Russia, as well as Ukraine’s ties with other nations. The rejection of most of Ukraine’s claims highlights the tribunal’s jurisdictional boundaries, which may become a topic of further debate in international law.
In light of the tribunal's decision, the implications for maritime operations in the region are significant. Notably, recent actions, such as the seizure of the bulk carrier Caffa by Sweden at Ukraine's request, highlight the ongoing complexities of international maritime law and enforcement in contested waters. The ruling underscores Ukraine's position as a coastal state and its efforts to protect its maritime interests.