Legality and Reality: The Eastern Flank and the Ottawa Convention

Russia’s aggression has reignited a debate long thought settled in Europe: whether anti-personnel mines (APMs) still have a place in deterrence and defence. The war in Ukraine demonstrates their continuing military utility, while also exposing the legal constraints and humanitarian repercussions states may face in the event of armed conflict if they remain bound by the Ottawa Convention.

In 2025, three years after Russia’s full-scale invasion of Ukraine, several eastern flank NATO member states announced their withdrawals from the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on Their Destruction (the Ottawa Convention).^[1] Ukraine, itself bound by the Convention, faces a legal dilemma of complying with international law (IL) while defending its territory against Russian aggression, including using landmines. Thus, before facing similar obstacles, Russia’s bordering NATO states left the Convention — a step that would have been unthinkable just a few years ago.

This decision has been heavily criticised by NGOs and states parties to the Convention. As for the United Nations, the High Commissioner for Human Rights, Volker Türk, was “gravely alarmed” by the path taken by the countries withdrawing.^[2] Moreover, NGOs emphasise that the use of APMs primarily harms civilians and that these humanitarian consequences outweigh any tactical advantages. Although modern APMs — including those envisioned for Baltic defence — can be equipped with self-destruct mechanisms, technical failures and other factors mean that the risk to civilians can never be completely eliminated.^[3] Many states are concerned about the erosion of the global disarmament framework, but some also recognise that it is exacerbated by Russia’s actions. Canada, a country deeply committed to the eradication of anti-personnel mines and a framework nation for NATO’s Forward Land Forces deployed in Latvia, has expressed its regret over the withdrawals from the Ottawa Convention, but also blamed these decisions on “Russia’s illegal invasion of Ukraine and its threatening behaviour toward other neighbouring states.”^[4]

The Convention was signed by 122 countries in 1997 and entered into force in 1999. By 2024, more than 165 states were parties to the treaty, although three of the five permanent members of the United Nations Security Council — China, Russia, and the United States — remained outside it. Russia’s western neighbours nevertheless gradually acceded to the Convention. Ukraine signed it in 1999, shortly before its entry into force, but ratified it almost seven years later, in 2005. Lithuania signed the Convention in 1999 and ratified it in 2003. Neither Estonia nor Latvia originally signed the treaty, but each later acceded to it — Estonia in 2004 and Latvia in 2005. Finland ratified the Convention in 2012, followed by Poland. Following Russia’s full-scale invasion of 2022, however, these states began reconsidering their commitments under the Convention, citing legal, political, and security concerns.

Mines in the Ukraine War: Shaping the Battlefield

APMs constitute only one category of landmine, alongside anti-vehicle mines, which fall outside the scope of the Ottawa Convention. Consequently, the tactical discussion in this policy brief addresses landmines generally, whereas the legal analysis focuses specifically on APMs.

In Russia’s war in Ukraine, both sides have employed landmines, albeit to different degrees and using different mine-laying techniques. Russian military doctrine, rooted in Soviet operational thinking, places heavy emphasis on mines for defence, reflecting Russia’s vast, flat, and open terrain facing the west, which lacks natural barriers. Historical traumas such as the German invasion during the Second World War, Russia’s own current imperialist ambitions, and heightened paranoia about NATO’s supposed aggressive intentions underpin Russia’s strategic focus on landmines. Russian doctrine also prioritises the attrition of enemy forces over mobility.^[5] As a result, Russia possesses the world’s largest stockpile of APMs.

The Armed Forces of Ukraine were compelled to adapt to this Russian attritional warfighting approach and to deploy landmines themselves

The Armed Forces of Ukraine (AFU) were compelled to adapt to this Russian attritional warfighting approach and to deploy landmines themselves, although on a smaller scale and with more deliberate tactics. Whereas Russian forces mainly rely on large and scattered minefields, Ukrainian forces have generally sought to anticipate likely Russian avenues of advance and mine them selectively.^[6] Thus, despite being a signatory to the Convention, Ukraine has become the most heavily mined country in the world.^[7]

Landmines offer tactical advantages and can serve as a force multiplier, particularly for defenders, by wearing down enemy forces, channelling their movements, and significantly slowing their advance. In countermobility operations, they are used to shape the battlefield in the defender’s favour by directing advancing forces into predetermined kill zones covered by artillery, aircraft, drones, or other direct fire. Rather than killing outright, landmines are designed to maim and incapacitate, requiring additional personnel for first aid and evacuation. Even when mine-clearance technology is available, advancing forces must proceed cautiously and slowly.^[8] Additionally, landmines have a profound psychological effect, creating fear and uncertainty among advancing forces, thereby undermining morale. In this sense, their psychological effect can be as effective as the physical damage created by their explosive ordnance.^[9]

The importance of landmines in Russia’s defence doctrine became particularly evident in 2022 and 2023. During the summer and autumn of 2022, Ukrainian forces liberated over 6 000 km² in the Kharkiv and Kherson regions in a sweeping counter-offensive that caught Russian forces off guard and forced them into disorderly retreats. In light of this defeat, Russian General Sergei Surovikin assumed command of Russian operations in Ukraine and, in anticipation of the Ukrainian 2023 summer offensive, ordered the establishment of a heavily fortified and layered defensive line stretching more than 800 km from the Zaporizhzhia Oblast to the Sea of Azov.^[10] This so-called “Surovikin Line” consisted of several layers incorporating defence obstacles, trenches, and among other fortifications and technologies, dense minefields.^[11] It provided defence in depth, allowing Russian forces to slow and exhaust advancing Ukrainian units and force them into positional warfare, more favourable to Russian doctrine. In doing so, it played a significant role in blunting the Ukrainian counteroffensive of 2023.

Ukraine’s Uncertain Legal Stance

Due to its intensive use of APMs following Russia’s invasion, Ukraine announced in July 2025 its intention to suspend the application of the Convention.^[12] Suspension of a treaty means the temporary cessation of the operation of all or part of a treaty.^[13] Although the Convention contains no explicit suspension clause, it may still be possible under the general principles of IL.

Article 20(3) provides that a state involved in an armed conflict cannot withdraw from the treaty until that conflict ends. In the meantime, the state party remains legally bound to it, which is exactly Ukraine’s situation. Its statement is therefore an attempt to escape its obligations under the Convention, since the state is currently not able to withdraw.

Ukraine subsequently sought to justify the suspension by invoking general IL. In June 2025, the Ukrainian Ministry of Foreign Affairs stated: “We emphasise that at the time of Ukraine’s signing and ratification of the Ottawa Convention, such circumstances did not exist and could not have been foreseen.”^[14] This argument can be interpreted as an invocation of the fundamental change of circumstances (rebus sic stantibus principle).

To understand this argument, it is useful to look into the Vienna Convention on the Law of Treaties (VCLT), which sets out how states are required to fulfil their obligations under international treaties.^[15] Article 62 of the VCLT provides that states cannot withdraw from or suspend a treaty based on the principle of rebus sic stantibus unless a fundamental change of circumstances has radically transformed the treaty’s obligations. In the Gabčíkovo-Nagymaros Case, the International Court of Justice recognised that this provision reflects customary IL, meaning that all states can refer to it.^[16] The Ukrainian arguments are nevertheless difficult to sustain in the present case, given that the Convention’s raison d’être is to restrain the use of APMs in armed conflicts in all circumstances.

If the suspension were found to be unlawful, other states parties to the Convention could seek to initiate legal proceedings against Ukraine. This would, however, first require establishing that the Convention creates obligations erga omnes partes, entitling any state party to invoke responsibility for another party’s failure to respect the treaty without being itself a victim of its breach.

The Withdrawal Rationale

The fact that Ukraine is unable to formally withdraw from its conventional obligations helps explain the decision of the Baltic states, Finland, and Poland to do so during the summer of 2025.^[17] Unlike Ukraine, these states are not engaged in an armed conflict with Russia and could therefore withdraw from the Convention within 6 months of notifying the UN Secretary-General, under Article 20(2).

The Baltic states, Finland, and Poland sought to withdraw while they still had the opportunity to do so lawfully

The same Article requires “a full explanation of the reasons motivating this withdrawal.” As justification, these states explicitly linked their decisions to Russia’s invasion of Ukraine. Estonia stated in its depositary notification: “The decision to withdraw from the Ottawa Convention has been taken under exceptional circumstances, prompted by the Russian Federation’s ongoing war of aggression against Ukraine.” Even before submitting the official notification, the defence ministers of Estonia, Latvia, Lithuania, and Poland jointly recommended a withdrawal, stating: “With this decision, we are sending a clear message: our countries are prepared and can use every necessary measure to defend our territory and freedom.”^[18]

These states, therefore, sought to withdraw while they still had the opportunity to do so lawfully. However, as Article 20(4) makes clear, withdrawal from the treaty does not affect a state’s obligations under general IL, including conduct in armed conflict (ius in bello). The fundamental rules of international humanitarian law must always be respected, and the withdrawing states reiterated their commitment to do so in their notification.^[19]

Mines in the Baltic Theatre

Given these legal realities, the Baltic states must reconcile their international humanitarian commitments with current requirements for deterrence and defence against Russia, providing a concrete example of how international obligations intersect with national defence planning.

In 2024, the Baltic states jointly decided to establish the Baltic Defence Line (BDL) along their borders with Russia, the Russian exclave of Kaliningrad, and Belarus. Construction has already begun, with the first bunkers and anti-tank barriers now in place. The concept foresees a defensive belt up to 50 kilometres deep that combines natural obstacles, such as Estonia’s Narva River and Lake Peipus, with additional fortifications and “anti-mobility installations” designed to impede mechanised advances and prevent infiltration.^[20] APMs are also included in the BDL concept but would be deployed only in the event of actual hostilities, not during peacetime.^[21]Poland’s East Shield programme envisions similar measures.

The Baltic states must reconcile their international humanitarian commitments with requirements for deterrence and defence

Anti-personnel and anti-tank mines could also play an important role in other scenarios, such as a Russian attempt to close the Suwałki Corridor. Here, mines, combined with the region’s wet and wooded terrain and limited motorway infrastructure, could create bottlenecks that expose advancing forces to concentrated attacks.^[22]

Ultimately, the public nature of these announcements by Finland, the Baltic states, and Poland carries significant psychological and deterrent effects, while also complicating potential Russian offensive planning. Just as the construction of the BDL is being conducted publicly and under Russia’s watchful eye, the signalling surrounding the potential deployment of mines must also be understood in strategic terms. It conveys the willingness and readiness of northern and eastern European states to defend themselves against aggression and thereby seeks to deter Russia from undertaking such actions in the first place. Should deterrence fail, mines could also fulfil important warfighting functions by shaping the battlefield to the defender’s advantage, controlling Russian advances, and ultimately helping to repel them.

^[1] United Nations, Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on Their Destruction (United Nations, 18 September 1997).

^[2] “UN Human Rights Chief Volker Türk gravely alarmed by steps to withdraw from anti-personnel mine ban convention,” Office of the High Commissioner for Human Rights, 2 July 2025.

^[3] Nathan Wood, “Embrace Poland and the Baltic States for Embracing Anti-Personnel Mines,” War on the Rocks, 6 June 2025; Erik Tollefsen and Pete Evans, “Do anti-personnel mines still have military utility in modern warfare?” International Committee of the Red Cross, 26 November 2025.

^[4] Government of Canada, “Statement by Canada – Thematic Debate: Conventional Weapons – 80th Session of the United Nations General Assembly – First Committee,” 23 October 2025.

^[5] Richard L. Garcia and Colin Colley, “Russian Minefield Tactics Pose Challenge to Mobility,” T2COM G2, 13 November 2024.

^[6] Matthew M. Schmunk, “Protection: Mobility and Countermobility,” in John A. Nagl Project Director Michael T. Hackett Chief of Staff (eds), A Long, Hard Year: Russia-Ukraine War Lessons Learned in 2023 (Strategic Studies Institute, January 2026).

^[7] “In Ukraine, tackling mine action from all sides to make land safe again,” United Nations Development Programme, 17 October 2024.

^[8] Michael N. Schmitt, “Cluster Munitions and Anti-Personnel Land Mines: An Explainer,” Lieber Institute West Point, 28 March 2025.

^[9] Jan Erola, “From Shield to Sword: The Offensive Potential of Modern Landmines,” Nordic Defence Review, 2026.

^[10] Schmunk, “Protection: Mobility and Countermobility.”

^[11] Dorsel Boyer and Jennifer Dunn, “Russia’s ‘Elastic Defense’ Technique Slowed Ukraine’s Advance,” T2COM G2, 29 March 2024.

^[12] United Nations, Depositary notification of Ukraine, C.N.385.2025 (United Nations, 21 July 2025).

^[13] Iain Cameron, “Treaties, Suspension,” in Max Planck Encyclopedia of International Law (Oxford Public International Law, December 2020).

^[14] “Statement of the MFA of Ukraine on the Decision to Suspension from the Ottawa Convention,” Ministry of Foreign Affairs of Ukraine, 29 June 2025. 

^[15] United Nations, Vienna Convention of the law of the Treaties (United Nations, 23 May 1969).

^[16] International Court of Justice, Gabčíkovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports (International Court of Justice, 25 September 1997).

^[17] United Nations, Depositary Notification of Estonia, C.N.360.2025 (United Nations, 27 June 2025); United Nations, Depositary Notification of Latvia, C.N.361.2025 (United Nations, 27 June 2025); United Nations, Depositary Notification of Lithuania, C.N.362.2025 (United Nations, 27 June 2025); United Nations, Depositary Notification of Finland, C.N.372.2025 (United Nations, 11 July 2025); United Nations, Depositary Notification of Poland, C.N.421.2025 (United Nations, 20August 2025).

^[18] “Statement by the Estonian, Latvian, Lithuanian, and Polish Ministers of Defence on Withdrawal from the Ottawa Convention,” Ministry of National Defence of the Republic of Poland, 18 March 2025.

^[19] Hans-Peter Gasser, “Humanitarian Law, International,” in Max Planck Encyclopedia of International Law, (Oxford Public International Law, December 2015).

^[20] International Institute for Strategic Studies, “Fortifying NATO’s Eastern Flank,” in The Military Balance 2026 (IISS, 24 February 2026).

^[21] “Baltic Defence Line,” Estonian Centre for Defence Investments.

^[22] Schmitt, “Cluster Munitions and Anti-Personnel Land Mines: An Explainer.”