Swamp defence reimagined – natural tank traps in the Baltics
The Baltic states—particularly Lithuania, and to some extent Latvia—have increasingly been discussing ways to strengthen the protection of their borders not only through traditional military means but also by using natural terrain obstacles, with marshes, bogs, and wetlands receiving special attention in this context.
The idea, often referred to as “swamp defence,” is not merely an environmental initiative but is also seen as a potential military tool for border protection. From 2026 onwards, Lithuania plans to launch a pilot project under which previously drained peat bogs and marshlands along border sections facing Belarus and Russia would be restored to a water-saturated state. Working jointly, the Ministry of the Environment and the Ministry of Defence argue that natural wetland habitats could hinder the movement of a potential hostile military column and thus, either on their own or in combination with traditional physical barriers, contribute to strengthening border security. This approach echoes historical experience, when marshes also played a defensive role in the Baltic region during the Middle Ages.
The military logic behind this concept rests on the basic assumption that water-saturated, boggy terrain physically impedes the advance of ground-based armored vehicles and other heavy military equipment. When considering the broader security environment shaping military strategies in the Baltic states, it is important to note that NATO’s eastern flank—including Estonia, Latvia, and Lithuania—has been continuously strengthening its resilience and deterrence capabilities in response to Russian aggression, which has manifested in airspace violations, hybrid threats, and military exercises.
In Latvia, the armed forces have explicitly emphasized that restoring bogs and marshy areas could enhance border-defence capacity, as these landscapes may form natural obstacles along the eastern border. This, in turn, could reduce the need to divert military resources elsewhere and increase the time available to organize defensive operations.
The Baltic states are not relying solely on this single measure; in parallel, they are also constructing conventional defensive lines, including mobility obstacles, trenches, anti-tank mines, and fortified positions, all designed to slow and complicate a potential adversary’s advance. In Lithuania, for example, plans include a three-tier, depth-based border defence system, in which the first line consists of immediate physical obstacles, while subsequent zones contain additional nodes and defensive structures.
The military use of natural obstacles is not without controversy: Russian commentators and propagandistic sources have mocked the swamp-defence plans, arguing that such measures cannot stop modern military technology. Nevertheless, defence decision-makers in the Baltic states maintain that, in light of both historical precedents and the current security situation, restored marshlands can serve as effective complementary elements within a layered, combined defence system, enhancing overall border security.
