Shifting Ground: NATO’s Eastern Border Strategy and the Return of Landmines

In June and July 2025, Poland, Finland, Estonia, Latvia and Lithuania formally announced their withdrawal from the Convention on the Prohibition of Anti-Personnel Mines. The so-called Ottawa Treaty prohibits the use of anti-personnel mines. The exit reflects the evolving threat landscape along NATO’s northeastern flank that borders Belarus and Russia. The states justify the move with the military lessons learned from the war in Ukraine and the growing pressure from Russian troop movements, hybrid operations and border provocations. Russia has used APMs in the war against Ukraine. For strategic reasons, President Zelensky announced Ukraine’s withdrawal from the treaty.

Key Take-aways

• For the first time, EU and NATO countries are coordinately withdrawing from an international disarmament agreement.
• Anti-personnel mines are to become an integral part of joint border defence systems (East Shield / Baltic Defence Line).
• The intended use is limited to defensive scenarios: deny access, restrict mobility, and channel enemy movement.
• The renewed deployment of APMs reflects a broader strategic shift, away from symbolic presence and toward operational defence capabilities.

Background

The Ottawa Treaty came into force in 1999. It prohibits the production, stockpiling, use and transfer of anti-personnel mines. To date, 164 countries have signed the treaty, including almost all EU states and NATO members. Anti-personnel mines (APMs) are intended as a deterrent. They are deployed to block terrain, control enemy movements and prevent mobility. However, their strategic purpose goes beyond this: they are also designed to injure and maim people, not necessarily to kill them, thereby tying up medical resources, burdening logistics, and reducing combat efficiency. Because of this, the Ottawa Treaty has long been regarded as a symbol of the humanization of armed conflict. The United States, China, Russia and Belarus have never signed the treaty. With Russia using APMs in the war in Ukraine, President Zelensky announced Ukraine’s withdrawal from the treaty in June 2025 for strategic reasons.

Analysis

The three Baltic states, Estonia, Latvia and Lithuania, share a 1,360 kilometers long land border with Russia and Belarus. Particularly critical is the 65-kilometre-wide Suwałki Gap between Poland and Lithuania. The corridor is NATO’s only land access to the Baltic states, flanked by Kaliningrad and Belarus. A coordinated offensive could cut this link and isolate the Baltic states. The Baltic Sea remains a strategically sensitive area, with Russian naval forces stationed in Kaliningrad and Kronstadt maintaining a constant presence.

In response, the Baltic states are jointly establishing the Baltic Defence Line, a border defence system with barriers, tank traps and bunkers. The forest- and lake-rich regions of eastern Latvia (Latgale) and eastern Lithuania (Aukštaitija) are particularly relevant. These are sparsely populated, topographically challenging areas with limited infrastructure. They are hardly suitable for a permanent troop presence, but offer potential axes for infiltration or hybrid operations, such as via the Russian-influenced Daugavpils. The potential use of anti-personnel mines can effectively block bottlenecks, paths and crossings here and restrict enemy movements in advance.

Poland also faces strategic vulnerabilities along its borders with Belarus and the Russian exclave of Kaliningrad. Both are potential starting points for conventional or hybrid operations. As NATO’s logistical backbone in the eastern flank, Warsaw has a key role to play, especially in protecting the vulnerable Suwałki Gap.

With the ‘East Shield’ project, Poland is building a multi-layered defence system along its eastern border. In addition to modern surveillance technology and permanent barriers, the selective use of anti-personnel mines is being considered, particularly in rough terrain, at river crossings or sensitive junctions.

Although Finland has not announced a dedicated border infrastructure project, its natural geography already provides a strong defensive buffer. The decision to withdraw nonetheless signals a strategic shift towards integrating mine systems into territorial defence planning.

Conclusion

The potential use of anti-personnel mines is a prime example of a security policy shift along NATO’s eastern flank. The former ‘tripwire strategy’ based on limited presence and symbolic deterrence is being replaced by a concept of forward, layered, and immediate defence. Since the NATO Summit in Madrid (2022), the guiding principle has been clear: deterrence starts at the border, not behind it. Large-scale infrastructure projects such as the Baltic Defence Line and East Shield embody this logic.

The coordinated withdrawal from the Ottawa Treaty marks not just a tactical realignment, but also a political signal: European frontline states are asserting more national autonomy in how they shape their border defence. This is not a departure from NATO, but a complement to the alliance strategy. It is grounded in national resilience and terrain-based denial. The planned reintroduction of landmines reflects a pragmatic, though controversial, response to the operational demands of deterrence along NATO’s eastern frontier.