On August 23rd, 1989, an estimated two million citizens from the countries of Estonia, Latvia, and Lithuania linked arms to form a human chain spanning the 600 km distance between the respective capitals of Tallinn, Riga, and Vilnius. The peaceful protest marked 50 years since the secret agreement known as the Molotov-Ribbentrop Pact between Nazi Germany and the Soviet Union, which the USSR used to justify occupation of the Baltic nations in 1940. The so-called Baltic Way demonstration influenced the Soviets to invalidate the pact, a crucial step in the eventual recognition of independence in the Baltic states.
Now the Baltic nations embark on a new kind of Baltic Way, this time connecting military defensive perimeters on their eastern borders through a project called the Baltic Defence Line (BDL). Announced jointly by the three nations’ Ministers of Defense on January 19, 2024, the BDL is intended to connect “anti-mobility installations” along the eastern flank of the region to deter Russian aggression and produce a capability to defend the territory “from the first meter,” a reference to NATO’s 2022 Madrid Summit declaration, which agreed that the Alliance would “protect our populations and defend every inch of Allied territory at all times.”
Like its peaceful forbearer, the BDL is strengthened from the collective cooperation between the three nations, acknowledging that their relatively small defense budgets, lack of defensive depth, and shared history of Russian occupation make them more vulnerable when they stand alone. But the plans announced to date are quite parochial and have faced criticism for the inordinate cost to taxpayers and landholders. It also presents a one-dimensional solution to a multidimensional defense problem; one that the same Madrid communiqué defined as a “360-degree approach, across the land, air, maritime, cyber, and space domains, and against all threats and challenges,” a fact that Latvia was reminded of recently when a Russian drone penetrated its airspace and crashed 90 km inland.
For the BDL to truly influence Russian decision-making and deter aggression, it must connect its defensive concepts in the same way its citizens connected their arms in the unbreakable chain between its capital cities, through sharing the burden of such a defense and inspiring collective action within their civilian populations to not only strengthen the physical space to defend but the will of the people to defend it.
The Baltic Eastern Flank
The hostile eastern flank of the Baltic region that borders Russia and its ally Belarus is approximately 1,360 km (~845 miles). Lithuania’s hostile border includes a western flank with the Russian exclave Kaliningrad Oblast, adding 275 km (~171 miles) to its defensive problem. Lithuania is also the principal defender among the Baltic nations for the Suwałki corridor, its 90 km border with Poland that is the shortest land bridge between Belarus and Kaliningrad. This analysis focuses on the hostile eastern flank only, but Lithuania’s western and Suwałki corridor dilemmas contribute to its defense posture.
Estonia has the smallest hostile land border and enjoys terrain features like the Narva River, and Lakes Peipus and Pihkva, that restrict overland movement on its eastern flank and reduce its most vulnerable terrain down to approximately 210 km (~130 miles). Latvia shares a 387 km (~240 miles) border with both Russia and Belarus, with multiple rail and surface roads facilitating cross-border maneuver, and virtually no terrain features impeding overland movement. Lithuania is similarly situated to Latvia but with nearly two and half times the border area to cover, more rail and surface roads crossing its hostile borders, and capital just 40 km from Belarus.
Baltic Defence Line Issues
The first issue with the BDL is unequal burden sharing. Estonia, Latvia, and Lithuania have each committed €60 million annually to the project, which is the cost estimate before factoring in land negotiations to install permanent defensive architecture in this area. €60 million is equal to 8% of the Latvian and Estonian defense budgets respectively, and only 2.8% of the Lithuanian defense budget. Reports also indicate that Lithuania will use this money to defend its western border and that the EU intends to defer some of the cost. The fact that Lithuania would pay the least but have the biggest defensive problem indicates that these estimates are unrealistic. For the BDL to be transparent and truly cooperative, it must achieve equal burden sharing relative to the percentage of each country’s defense budget.
The next issue is the cost to landholders in the eastern region of the Baltic nations. It is safe to assume that significant concessions from the government will be needed to convince citizens to give up parts of their land for peacetime war preparations, and surveys suggest that ethnic identity could further complicate the negotiations in Estonia and Latvia. According to a 2024 survey commissioned by the Ministry of Defense, 67% of ethnic Estonians would give up their land to defense forces if Estonia was attacked, as opposed to only 38% of non-ethnic Estonians. The Estonian plan features construction and installation of approximately 600 bunkers, some of which would be built in Ida-Viru county in northeast Estonia; the only county in Estonia where ethnic Russians outnumber ethnic Estonians at a rate of 3.5 to one. In Latvia, at the major ground crossing points in the municipalities of Ludza, Viļaka, and Daugavpils, the percentage of ethnic Russians is higher than the national average, and Russian is the dominant ethnicity in the Belarussian border municipality of Daugavpils. Even in southeast Estonia, where the majority of the bunkers would need to be emplaced and the ethnic Estonian population outnumbers the Russian population three to one, citizens have sought to halt the expansion of the Nursipalu training area, signaling that even ethnic Estonians on the front line with Russia are uncomfortable with the government taking their land.
While prepared defensive positions have helped impose high costs on the Russian armed forces in Ukraine, the Latvian and Estonian land acquisition plans — particularly in areas where ethnic Russians live — could risk escalating tensions with Russia, which has used flimsier pretexts for defending its diaspora in the past. The Lithuanian plan to preposition engineer assets in critical locations is a more preferred way to establish these defensive positions and avoid costly land grabs. Additionally, highly mobile artillery systems, man-portable air defense and anti-tank systems, and large amounts of low-cost unmanned aerial vehicles are a few examples of how to keep the cost-to-kill ratio low, trade space for time, and stay out of citizens’ backyards during peacetime. The countries should also spend money on conducting annual joint exercises with active and reserve soldiers on each other’s borders to ensure they understand how to hand off potential targets along the BDL — a critical demonstration for an integrated defensive posture.
The last issue with the BDL addressed here is the willingness and capability of the citizenry to defend, using Estonia’s defensive problem and the October 2023 Hamas attack on Israel for context. Estonia maintains an active-duty force of 4,200 across all components, with 38,800 reservists in “permanent readiness” status, and up to 230,000 citizens who have “military obligations” but do not actively practice. If the 600 proposed bunkers are to be manned immediately, it will come from the regional ready reserve forces who will need to exercise this mission at least twice a year to follow the Israeli reserve model.
At the 2024 Annual Baltic Conference on Defence, a senior Israeli military official recounted the mobilization of Israeli reserve forces in response to the Hamas attack on October 7, 2023, observing that the country’s reservists helped resecure Israel’s border with Gaza in a matter of hours. For context, Israel secured a border that is approximately 59 km (~37 miles), with established defensive positions, against a non-state actor, and a seasoned reserve force that is estimated to be 220,000. Estonia, which has the simplest ground defensive problem of any of the Baltic nations, must secure a border 3.5 times larger than the size of Israel’s border with Gaza, against a determined nation-state actor, with less than one-fifth of the combat power. Moreover, only 48.5% of Estonians in the 20-39-year-old demographic would commit to taking up arms to defend their country.
Conclusion – A ‘Baltic Way’ Defence Line
Suppose the defense establishments of the Baltic nations want to present a credible deterrent across their eastern flank. In that case, they must share the cost of such an endeavor and put those funds toward useful purchases, like weapon platforms that have seen success on the battlefield in Ukraine, and large-scale exercises including mass mobilization of reservists and cross-border coordination. They must not disenfranchise the segment of their population most susceptible to Russian influence, or inadvertently provide Russia pretext for defending the Russian diaspora. Most importantly, they must harness the spirit of the Baltic Way and inspire their citizens to want to defend every inch of their territory by metaphorically locking arms across the eastern flank of the Baltics.