By Olha Hembik | 2025-04-29

WARSAW -- A Russian advance of merely 65km overland could doom NATO.

That strip of land, known as the Suwalki Gap, has long been seen as one of the alliance's most vulnerable points. Sixty-five kilometers is the length of the Polish territory between Kaliningrad province, Russia, and Russian ally Belarus.

Now Lithuania is moving to upgrade a critical road through the gap to speed the movement of troops and equipment if conflict breaks out.

If Russia launched an attack out of Kaliningrad and NATO could not hold the Suwalki Gap, the Kremlin could sever the only land connection between the Baltic states and the rest of Europe.

Kaliningrad's heavy militarization compounds the threat. The Russian exclave hosts troops, the Baltic Fleet, fighter jets and an arsenal of Iskander missiles capable of carrying nuclear warheads. Following Russia's full-scale invasion of Ukraine in 2022, fears about the Suwalki Gap's security have only intensified.

A 'military Schengen zone'

Two main roads cross the Suwalki Gap. One connects Kaunas, Lithuania, with Warsaw and is part of the Via Baltica military corridor, the main route for sending allied reinforcements. The other is a civilian road linking the Lithuanian capital of Vilnius and Augustow, Poland.

"These roads ... have always been part of our civil-military planning as key ground routes for allied support during a crisis," Lithuanian Deputy Defense Minister Tomas Godliauskas told POLITICO in April.

Lithuania and Poland are now upgrading the Vilnius-Augustow road to allow military use, extending infrastructure beyond the Via Baltica.

Reinforcing the Suwalki Gap itself is difficult, Denis Kishinevsky, a Lithuanian journalist covering politics for Current Time, told Kontur.

"It won't be possible to declare this territory a fully military protected zone -- there are villages, settlements and quite fertile arable lands, and people live there," he said. "Plus, there is constant passenger and freight traffic -- it will not be shut down."

For years, Lithuania and Poland have sought to secure the corridor through regular military exercises. Kishinevsky recalled exercises in 2024 that Poland and Lithuania conducted to thwart a hypothetical Russo-Belarusian attempt to block the gap.

"According to NATO's regional plans, Poland should come to the rescue, and the main focus is on this," he said.

Discussions are under way about creating a "military Schengen zone," allowing Polish and Lithuanian military vehicles to cross borders freely in the event of a threat.

The upgrade project for the Vilnius-Augustow route involves rebuilding 113km of road and renovating eight bridges. "We're discussing how to address GPS [Global Positioning System] spoofing and jamming from Russia," Godliauskas told POLITICO, adding that this "is already affecting our civil aviation and navigation systems." Work is scheduled for completion by 2028.

NATO's weak spot

Then-Estonian President Toomas Hendrik Ilves coined the term "Suwalki Gap" in 2015, when he compared the region to the Fulda Gap, a potential Soviet attack route during the Cold War, according to Rzeczpospolita.

In 2022 POLITICO described the area as "the most dangerous place on Earth."

"In this area, more and more potential and real threats related to the control of illegal migration, as well as all kinds of sabotage ... will be concentrated," analyst Krzysztof Fedorowicz wrote in 2023, as quoted by Rzeczpospolita in March.

"These will mainly be information and psychological operations aimed at activating Polish and Lithuanian forces and resources, distracting attention and creating a certain kind of incitement and additional tension," Fedorowicz said in 2023.

Fedorowicz cited the likelihood of sabotage in the forested area where Poland, Lithuania and Belarus converge and where small military units can move undetected.

Another source of concern is the Zapad-2025 Russo-Belarusian military exercises, scheduled for mid-September, France's RFI reported in February.

Russia, before invading Ukraine in 2022, conducted the Zapad-2021 drills with Belarus the year before, RFI added.

"The military vulnerability of the Suwalki Gap deserves attention. It's easy to shoot up the corridor, and from both sides -- from Krulevets [Kaliningrad] and Belarus," Jerzy Mazur, a military analyst, veteran of peacekeeping missions, and retired Polish army officer, told Kontur. "In the event of an attack from two directions, Poland could suffer significant losses."

"Even a temporary blockade of this section of land could have serious consequences for regional stability and NATO's defensive capability," he stressed.

A constant threat

The threat from the Suwalki Gap has always remained, Ukrainian Lt. Gen. (ret). Ihor Romanenko, former deputy chief of the Ukrainian general staff (2006-2010), said.

Russia poses a danger there because of "capabilities that [it] could effectively use during an offensive," he told Kontur.

Citing NATO intelligence, Romanenko claims that the Russian army "has plans to enter Poland and the Baltic states." Coordinated actions by all European countries would be necessary if Russia attacked the area, he said.

"Countries... need to prepare, including by mining borders and fortifying roads," Romanenko said.

Russian President Vladimir Putin's authoritarian control of the military lets him decide more quickly than European militaries can, he said.

"War requires quick decisions. The Russians can break through corridors and simultaneously drop paratroopers behind enemy lines," Romanenko said.

One solution, he argued, would be for European countries to allocate 2–3% of their GDP to defense.

At least €70 billion is needed to urgently upgrade NATO's rail, road, sea and air corridors for military use, European Union Commissioner for Defense and Space Andrius Kubilius, a former Lithuanian prime minister, estimated, according to a March Euronews report.