On July 17, 2025, Ukraine made the decision to halt its participation in the Anti-Personnel Mine Ban Convention, also known as the Oslo-Ottawa Convention. This move was communicated to other State Parties through the UN Secretary General, who serves as the treaty’s official repository. The rationale behind Ukraine’s suspension revolves around the principle of reciprocity. Russia, despite not being a signatory to the Convention and therefore not bound by its stringent provisions, has utilized anti-personnel mines in multiple instances during the ongoing armed conflict with Ukraine. Thus, in order to establish a sense of fairness in the use of these mines and prevent being at a disadvantage during the conflict, Ukraine decided to suspend its commitment to the Oslo-Ottawa Convention.
Nevertheless, Ukraine’s suspension does raise legal concerns concerning treaty law. The Oslo-Ottawa Convention, like other international humanitarian law treaties, addresses the issue of withdrawal. In cases where a State Party is engaged in armed conflict, Article 20(3) of the Convention postpones the effectiveness of the state’s withdrawal until the end of the conflict. Additionally, the Convention does not explicitly include a provision for suspension, and the absence of such a clause implies that suspension is not permissible under normal circumstances without a valid reason rooted in general international treaty law.
In response to Ukraine’s suspension, Switzerland and a few other states formally objected, labeling the suspension as inadmissible. The objections were transmitted by the depositary to the Assembly of States Parties, which convened in December 2025. Switzerland strongly expressed its concerns regarding Ukraine’s decision to suspend the application of the Convention, citing the ongoing conflict with Russia and condemning Russia’s use of anti-personnel mines on Ukrainian territory. The Assembly’s final report deemed Ukraine’s suspension incompatible with the Convention and called upon Ukraine to remain actively involved in the Convention’s framework.
The challenge of interpreting the suspension of a treaty under the 1969 Vienna Convention on the Law of Treaties (VCLT) and customary international law was acknowledged in light of Ukraine’s actions. The conditions for suspension under the Oslo-Ottawa Convention and the VCLT are intricate, and the applicability of these legal provisions remains uncertain.
Overall, Ukraine’s suspension of the Oslo-Ottawa Convention prompts a deeper examination of the legal implications and potential consequences, particularly during armed conflicts. The complexities surrounding the suspension highlight the need for thorough deliberation and adherence to established international legal frameworks in addressing treaty obligations during times of conflict.
