In the Winter War (1940), Finland’s swamps proved to be a major obstacle for Russian forces, particularly mechanized and motorized units. The swamps served as a natural anti-tank ditch. Ukraine has successfully used water obstacles to block potential offensive avenues of attack or channel Russian offensive thrusts. For example, when a Russian column approached Kyiv in February 2022, Ukrainian forces destroyed the Kozarovychi dam on the Irpin River (14 miles north of Kyiv). The water obstacle stalled the Russian advance.

Now, the Finnish government is considering a proposal to restore or expand swampy areas (wetlands) along the Finnish-Russian border. Water acts as a fixed fortification of sorts, and Ukraine’s successful use of sophisticated, integrated defensive zones has led to a revival of fixed defenses in Eastern Europe.

The concept of a defensive zone is critical. Fortifications and obstacles are part of a defensive scheme that includes all-around defense (covering ground and airspace). Zone defense involves launching quick, coordinated counterattacks from fortifications and camouflaged redoubts. Drones could deliver these counterattacks, striking enemy forces slowed by obstacles or driving them into obstacles and minefields.

Poland’s East Shield fortification zone is the premier conceptual example. East Shield features numerous anti-tank ditches. Early rough sketches of East Shield (May 2024) also included water obstacles. The Polish Ministry of Defense now confirms that restoring or enhancing swampland will be part of the project. Reforesting border areas will also play a role in denying a “high-speed axis of attack” to Russian forces or channeling a Russian attack. East Shield will ultimately fortify 700 kilometers of the Polish-Russian border.

Approximately ten percent of the territory of Estonia, Latvia, and Lithuania is classified as natural wetland or marsh. These Baltic wetlands along the Russian border already provide a limited barrier. Lithuania now states it intends to incorporate its wetlands into its anti-Russian fortification and obstacle plans. (AB)