Baltic defence line: Fortifications alone won’t stop Russian assault

The Baltic states — Estonia, Latvia, and Lithuania — face a stark strategic challenge: their flat, open terrain offers little natural defence against a Russian attack. 

Unlike Switzerland or other naturally defensible regions, the Baltics’ flatlands, lakes, and swamps provide only limited impediments to an aggressor’s advance. In response, the three nations have announced plans to build a coordinated “Baltic Defence Line,” a network of fortifications, obstacles, and anti-armour measures designed to slow an invader and buy time for a larger defensive response, according to an analysis by CEPA. 

Estonia plans to construct 600 bunkers along its 300-kilometer border. Latvia is deploying anti-tank obstacles and “dragon’s teeth” to hinder mechanised forces.

Lithuania’s plan, the most elaborate, envisions a 50-kilometer-deep multi-layered system: a first layer along the border with ditches, dragon’s teeth, minefields, trenches, and strongpoints; a second line with additional trenches and wired bridges for demolition; and a third layer using felled trees, more trenches, and additional demolition-ready bridges. 

Collectively, these measures aim to impede an attacking force, channel it into predictable paths, and increase the effectiveness of defending troops.

Historically, fortifications have been both force multipliers and potential liabilities. The French Maginot Line and Israel’s Bar-Lev Line demonstrate that static defences can amplify defensive capacity but also create a false sense of security if mobile reserves are inadequate or if high command fails to respond to enemy maneuvers.

The Maginot Line, for instance, was bypassed through the Ardennes Forest, and the French could not redirect forces in time to counter the German breakthrough. Similarly, Israel’s lightly manned Bar-Lev Line was quickly overcome when Egyptian forces launched a coordinated attack, demonstrating that fortifications alone cannot stop a determined, well-coordinated offensive.

For the Baltic states, the Defence Line is intended to serve as a tactical tool rather than a standalone solution. Its primary functions are to slow an aggressor’s advance, impede logistics, protect key terrain, and buy critical time for mobilising reserves and coordinating allied reinforcements.

Estonia, with fewer than 8,000 active personnel, and lightly armed reservists, relies on the broader NATO framework for the bulk of counteroffensive capability. NATO’s current presence in the region includes four battlegroups and a German armored brigade in Lithuania. While this enhances deterrence, it would serve largely as a tripwire in the event of a large-scale offensive.

The ultimate challenge is timing and coordination. A rapid, fully equipped NATO response is essential for translating the line’s tactical value into strategic defence.

Any delay — whether due to logistical constraints, limited European military capacity, or uncertain political will — could tempt overreliance on static fortifications. CEPA’s analysis underscores that fortifications are only one component of an integrated defence strategy, which must also include mobile reserves, airpower, intelligence, and allied cooperation.

By Sabina Mammadli