The Baltic plan to win the war that has yet to come
Introduction
It is no secret that the Baltics have long viewed their eastern neighbor with suspicion. After all, it was only 30 years ago that the last Russian forces left these countries. With the invasion of Ukraine in 2022, these lukewarm relations escalated into full Cold War-esque hostility. Russia has indicated through both actions and words that it wants to re-incorporate the lost territories of Estonia, Latvia, and Lithuania into “the Motherland.” In 2023 the former president Dmitry Medvedev referred to Baltic countries as “our Baltic provinces.” Many in the Baltics now see war with Russia not as a question of “if”, but rather “when”. This belief is reinforced by Russian invasions of Georgia and Ukraine, countries that, like the Baltics, were once part of the Soviet Union and the Russian Empire.
In light of this, the governments of the Baltic countries have decided to band together to create a defensive line to resist another potential Russian invasion. The Baltic Defense Line was announced on January 19, 2024, during a joint meeting of the Ministers of Defense from Latvia, Estonia, and Lithuania. The line will feature anti-mobility defensive installations and bunkers along the borders of Estonia, Latvia, and Lithuania with Russia and Belarus. Together with border fortifications in Norway, Finland, and Poland, this initiative will enhance the security of Europe as a whole by creating a continuous line of defense against potential attacks. These fortifications act as deterrents, complicating any plans for rapid invasions while also improving NATO's ability to defend the region.

History of Warfare and Defensive Lines in the Area
Throughout history, many defensive lines facing the east have been constructed in the Baltics. For example, Hermann Castle in Narva, which still marks the border between Estonia and Russia, was built by the Danes in the 13th century as a border fortification against Novgorod and the Pskov Republics. A belt of castles stretching from Narva to Daugavpils served as the main defense line of the Livonian Confederation until it was breached by Ivan the Terrible’s forces during the Livonian War in the 1550s. Efforts to improve border defenses continued until 1710 when the region came under the control of the Russian Empire, thereafter shifting defensive priorities as the area became integrated into the empire, reducing the perceived need for extensive border fortifications. While the Estonian and Latvian wars of independence were characterized by maneuver warfare, defensive lines were built in Estonian areas such as Narva and Petseri. Unlike Finland, which constructed the Mannerheim Line in the 1920s, Estonia and Latvia did not establish strong border defenses during that period. It was only in the 1930s, amid a rapidly deteriorating security climate, that Estonia devised plans for the “Laidoner Line,” though it remained largely incomplete due to the Soviet occupation in 1940.
During World War II, German forces established multiple defensive lines using natural boundaries such as the Sinimäed hills and the Narva River on the Leningrad front. While these defensive operations inflicted around 500,000 casualties, they were eventually abandoned due to breakthroughs farther south. These historical defenses, though shaped by the technologies and tactics of their time, underline a consistent theme: the necessity of preparing for invasions from the east—a lesson that continues to shape the Baltic states' modern strategies and resonate within their societal consciousness.

Hedgehog Defense
The Baltics have much to be concerned about. With a combined population of only 6 million people, their resources, both in terms of manpower and funds, are severely limited. Unlike most Western armies, the Baltic countries adhere to a concept of total defense, mobilizing their entire populations for the war effort. While in most NATO members the fighting is left to the small professional armies, the total defence model establishes that during the war, every available resource must be part of the country’s defence. While NATO provides a broader framework for regional security, the Baltic model emphasizes self-reliance and rapid mobilization as a first line of defense. Despite this, their militaries, while exceeding expectations thanks to their reserve forces, lack significant monetary resources. This has forced them to focus on essentials, foregoing advanced military technology. Without a sizable navy, air force, or tank fleet, the Baltic countries have adopted a defensive strategy that has been christened as “Hedgehog”. This strategy relies primarily on light infantry forces that will dig in and hold their positions against overwhelming odds until NATO allies, particularly the United States, are able to rally their troops and reinforce the region.
Since 2014, the Baltic militaries have undergone significant changes, from revising the very core principles of total defense to upgrading the more minute details of the equipment. Lithuania and Latvia reintroduced national conscription in 2014 and 2022, respectively. Previously, Baltic defense strategies emphasized maneuver warfare and guerilla campaigns to weaken occupying forces until NATO allies gather enough strength to re-liberate the Baltics. This model has now been reworked. The Russo-Ukrainian war has established that giving up territorial control would be too costly, both for the civilians and for the soldiers that need to re-liberate those areas. Moreover, in the eyes of Baltic politicians the probability of political deadlock over decisions to liberate Baltics, if they get occupied, is too great. Increased military spending over the last decade has allowed the Baltics to upgrade their equipment, and since 2022 the focus has increasingly shifted towards static warfare, including the use of long-range weapons. Lessons learned from the war in Ukraine have led all three countries to invest heavily in medium and long-range weapons capable of targeting supply bases and troop concentrations beyond the frontlines.

No Room for Mistakes
The Baltics suffer not only from a lack of resources but also from limited strategic depth. For example, during the 2022 Russian invasion of Ukraine, Russian forces reached the Kyiv suburb of Obolon—approximately 100 kilometers from the border—within 24 hours. In the Baltics, 100 kilometers spans half the width of the country and includes five of the region’s ten largest cities.
Nowhere is this weakness more on display than in Lithuania. The Lithuanian capital, Vilnius, is located less than 35 kilometers from the Russo-Belarusian border, far closer than the distance between any of the major Ukrainian cities and the Russian border. Even without crossing the border, Russian forces could target Vilnius, the biggest city of Baltics, with artillery fire. Lithuania shares nearly 1,000 kilometers of border with Belarus and Kaliningrad. While the Kaliningrad border largely follows rivers, offering some natural defense, the rest of Lithuania’s border is a patchwork of small forests and open fields. Most of Lithuania’s population resides in a corridor between these states, which would likely bear the brunt of an invasion aimed at cutting the vital Suwałki Gap.
Latvia faces similar challenges; although parts of its eastern border are covered by forests and swamps, significant open areas and key towns like Rēzekne and Daugavpils are also in close proximity. Historically, defenses in eastern Latvia were breached during the independence wars as well as World War II, leading to the division of Latvia and attacks on Estonia from the south-east. Since World War II, border areas in Latvia and across the Baltics have undergone significant reforestation due to economic transitions and Soviet collectivization.
Out of all three Baltic sisters, Estonia has by far the most advantageous border. About half of its border with Russia is covered by Lake Peipus, providing a natural defensive barrier. The northeastern border runs along the Narva River and is flanked by heavily forested and swampy areas, forcing any invading force into a narrow corridor between the forests and the Baltic Sea. However, the southeastern border, while hilly and forested, has historically proven less defensible.

Plans for a Baltic Defense Line
These differences in defensiveness are reflected in the implementation of the Baltic Defense Line. Latvia and Lithuania plan to build bunkers primarily along main roads and likely invasion routes, as the entire border is too long to be covered with current budget allocations. Estonia, however, intends to construct 600 bunkers capable of housing 6,000 defenders. All three countries have agreed to deploy a mix of anti-mobility installations such as dragon’s teeth, anti-tank hedgehogs, and anti-tank mines that will be stored in support points and storage areas behind the defensive line. In Estonia, the line’s depth is expected to reach up to 40 kilometers, with bunkers acting as strongpoints that can be reinforced with minefields and trenches when necessary. The Estonian government has stressed that these bunkers will be built with minimal environmental impact and disruption to local communities, as in 2023 and 2024 there was some dismay over the expansion of the Nursipalu training area for NATO and Estonia’s 2. Infantry Brigade troops.
Construction has already begun in Latvia and Lithuania, with anti-tank installations like dragon’s teeth and hedgehogs stored near the border. Estonia plans to start bunker construction in 2025, having already completed tests of different bunker models. These modular bunkers, measuring 35 square meters and housing 10 soldiers, will be built 2 meters underground and designed to withstand direct hits from standard 155mm artillery shells.
While these plans reflect the Baltic states’ view of Russia as a long-term threat, they do not suggest an immediate danger from the Russian Federation. While Russia has shown great willingness to reclaim territories of the USSR, the ongoing war has depleted its resources to a point where invasion of Baltics is not viable in the near future. Before the 2022 invasion, Russia's military took almost a year and a half to build up its forces on the Ukrainian border. If an invasion of the Baltics followed a similar model, most additional fortifications—including trenches and minefields—could be prepared by reserve units in a short time. As former Estonian armed forces head Martin Herem stated, “I don’t think we should build it [the Baltic Defense Line] like the Maginot Line or a similar structure. However, we must be able to create such a line of defense in an extremely short time—just a couple of days.”

Wars to Come
Plans for a defensive line against Russia reflect the historical distrust in the Baltics towards their larger eastern neighbor. This adversarial stance is to all intents and purposes confirmed by the aggressive posture taken by Russia and wars fought in Ukraine, Georgia and Moldova. Baltics, which cannot afford the luxury of defence in depth, have now decided that the threat of Russian aggression has reached the level of the 1930s. In the eyes of the Baltic states the lack of manpower and resources in these small countries necessitate the construction of this defensive line as a force multiplier. Only time will tell if these fears are justified or if these fortifications mark the end of centuries of conflict over this small seaside region.
Bibliography
Estonian Ministry of Defence. National Defence Development Plan 2031. https://riigikaitseareng.ee/2031/en/
://www.kaitseinvesteeringud.ee/en/baltic-defence-line-2/
Latvian Ministry of Defence. Border Fortification. https://www.mod.gov.lv/en/border-fortification
Abromaitis, Ž. (2024, November 2). Baltijos šalys braižo gynybos linijos kontūrus: bunkeriai ir kontrmobilumo priemonės. LRT.lt. https://www.lrt.lt/naujienos/pasaulyje/6/2402507/baltijos-salys-braizo-gynybos-linijos-konturus-bunkeriai-ir-kontrmobilumo-priemones
Piirimäe, K. (2017). Preparing for War in the 1930s: The Myth of the Independence War and Laidoner's "active defence". Estonian Yearbook of Military History, 7 (13), 116-150.
Treufeldt, R. (2010). Laidoneri liin kui Narva tabalukk. Tehnikamaailm, 5, 60-63.
Laar, M. (2006). Sinimäed 1944: II maailmasõja lahingud Kirde-Eestis. Tallinn: Varrak.
Institute for the Study of War. Russian Offensive Campaign Assessment, February 25, 2022. https://www.understandingwar.org/backgrounder/russia-ukraine-warning-update-russian-offensive-campaign-assessment-february-25-2022
Sargs.lv/LRT.lt. (2024, February 5). Igaunijas aizsardzības spēku komandieris: Baltijas aizsardzības līnija nelīdzināsies Mažino līnijai. https://www.sargs.lv/lv/viedoklis/2024-02-05/igaunijas-aizsardzibas-speku-komandieris-baltijas-aizsardzibas-linija
Askew. J. (2023, May 17). Ex Russian PM Dmitry Medvedev claims Baltic countries belong to Russia. Euronews. https://www.euronews.com/2023/05/17/russias-dmitry-medvedev-claims-baltic-countries-belong-to-russia
Kommentarer