Chokepoint · Poland and Lithuania
Suwałki Gap
OpenUpdated November 1, 2026
The Suwałki Gap is the 104 km border between Poland and Lithuania. It runs between Belarus and Russia's Kaliningrad exclave, which are about 65 km apart there. It is the Baltic states' only land link to the rest of NATO and the EU. Two roads and one railway cross it.
- Width
- 65 km
- from Belarus to Kaliningrad
- Border length
- 104 km
- between Poland and Lithuania
- Links across it
- 2 roads, 1 railway
- the Via Baltica is the main road
Where is the Suwałki Gap?
The gap is the border between Poland's Podlaskie region and Lithuania. On the Polish side the main towns are Suwałki and Sejny. On the Lithuanian side: Lazdijai, Kalvarija and Marijampolė. In a straight line, Belarus is about 65 km from Russia's Kaliningrad exclave. The border between Poland and Lithuania runs for about 104 km between them.
The land is hilly and cold, shaped by glaciers. Deep lakes (Hańcza and Wigry), thick forest, river valleys and marshes cover the area, and unpaved roads become impassable when wet. A 2018 report by the Center for European Policy Analysis said the terrain favors defenders, though other analysts say tanks can cross it.
Only two main roads and one railway cross the gap. The Via Baltica runs through the Budzisko-Kalvarija crossing as the S61 in Poland and the A5 in Lithuania. Poland finished its section on October 2, 2025. The second road crosses at Ogrodniki-Lazdijai. The single-track, non-electrified railway runs through Trakiszki in Poland and Mockava in Lithuania.
Estonia's former president Toomas Hendrik Ilves says he coined the term in 2015. Ben Hodges, a retired US general who commanded the US Army in Europe from 2014 to 2017, made it widely known.
POLAND
LITHUANIA
BELARUS
RUSSIA(Kaliningrad) Suwałki Marijampolė Kaunas Vilnius Grodno Białystok Ełk Łomża 65 km
POLAND
LITHUANIA
BELARUS
RUSSIA(Kaliningrad) Suwałki Marijampolė Kaunas Vilnius Grodno Białystok Ełk 65 km
Why is the Suwałki Gap called NATO's weak spot?
The gap is the Baltic states' only land connection to the rest of NATO and the EU. If Russian and Belarusian forces closed it, Lithuania, Latvia and Estonia would be cut off by land. A 2016 RAND Corporation study, based on wargames in 2014 and 2015, found that Russian forces could reach the outskirts of Tallinn or Riga within 36 to 60 hours.
NATO placed battlegroups in Lithuania and Poland in early 2017 in response. Germany's 45th Panzer Brigade took over the Lithuanian battlegroup in February 2026 and had about 1,800 troops by that date. Germany plans to grow the brigade to about 4,800 soldiers plus 200 civilians by the end of 2027. About 10,000 US troops were in Poland as of May 2026.
On May 14, 2026, the Pentagon canceled the rotation of an armored brigade of about 4,200 troops to Poland. On May 21, 2026, President Trump said 5,000 additional troops would go to Poland. Poland formally asked for a permanent US base on June 3, 2026. In Lithuania, a US rotation left in June 2026 with no replacement. New 1st Infantry Division troops began arriving at Pabradė in mid-October 2026.
Forces on both sides of the gap
KaliningradBaltic Fleet, 11th Army Corps (formed April 1, 2016), Iskander-M missiles permanently since February 2018
BelarusRussian tactical nuclear weapons since June 2023 (by Russia's and Belarus's account); an Oreshnik missile unit on duty since December 30, 2025, in eastern Belarus
Germany's 45th Panzer BrigadeAbout 1,800 troops in Lithuania after February 2026, about 4,800 planned by the end of 2027
United StatesAbout 10,000 troops in Poland as of May 2026; a new rotation arrived at Pabradė, Lithuania, in October 2026
What have Russia and Belarus done near the gap?
On June 18, 2022, Lithuania stopped EU-sanctioned goods moving by rail to Kaliningrad. Russia threatened a response. On July 13, 2022, the European Commission said sanctioned goods could transit by rail if volumes stayed within a three-year average. The rail route to Kaliningrad runs through Vilnius and Kaunas and does not cross the gap itself.
Russia and Belarus hold Zapad military exercises on a regular cycle. Zapad-2017 officially had 12,700 troops. Western estimates put the real number at 48,000 or even 100,000. Zapad-2025 ran from September 12 to 16, 2025. Lithuanian intelligence estimated about 30,000 troops in total. Poland closed its Belarus border from September 12 to 25.
In July 2023, Belarusian President Alexander Lukashenko said Wagner fighters wanted "an excursion to Warsaw." Poland's prime minister, Mateusz Morawiecki, said more than 100 Wagner fighters had moved toward the gap near Grodno. On the night of September 9 to 10, 2025, about 19 to 23 Russian drones entered Polish airspace, and Poland asked for consultations under Article 4 of NATO's treaty. On September 23, 2026, a Russian helicopter from Kaliningrad crossed into Polish airspace for 42 seconds. The gap itself has not been closed. In 2026 the pressure has come in other forms: smuggling balloons from Belarus closed Vilnius airport more than ten times, and aircraft and migrants have crossed the borders.
Pressure on the gap
June 18, 2022Lithuania stops EU-sanctioned goods by rail to Kaliningrad (eased July 13, 2022)- July 2023Wagner fighters near Grodno; Lukashenko's "excursion to Warsaw" remark
September 12–25, 2025Zapad-2025 drills; Poland closes its Belarus border- October 2025Lithuania closes its Belarus crossings over smuggling balloons
- September 23, 2026A Russian helicopter from Kaliningrad crosses into Polish airspace for 42 seconds
How are Poland and Lithuania defending the Suwałki Gap?
Poland's East Shield program covers about 700 km of its borders with Kaliningrad and Belarus, with completion planned for 2028. The 2026 target is about 260 km secured. Several dozen unarmed German army engineers have helped since June 2026, mostly around the gap. Lithuania approved a 20 m-wide strip of engineering obstacles along its Belarus and Kaliningrad borders by the end of 2028, with bridges fitted for demolition.
Both countries left the Ottawa treaty banning anti-personnel mines. Lithuania's withdrawal took effect on December 27, 2025. Poland's took effect on February 20, 2026. Lithuania approved a training ground at Kapčiamiestis, next to the gap, on April 23, 2026. It covers about 14,600 hectares and is planned for brigade-size drills by 2028.
Poland and Lithuania ran Brave Boar 2026 from June 16 to 26, with 6,500 Polish troops and Lithuanian and French forces defending the gap. On October 5, 2026, Poland's and Lithuania's interior ministers announced an evacuation plan for about one million Baltic residents through the gap. On October 6, 2026, Lithuania's parliament voted 106 to 18, in a first vote, to remove the constitutional ban on nuclear weapons and foreign bases. Kremlin spokesman Dmitry Peskov said Russia "will have to take all necessary measures." The final vote is set for January 12, 2027. Lithuania doubled patrols on its Kaliningrad border in October 2026.
Defending the gap
- East ShieldAbout 700 km of borders with Kaliningrad and Belarus; 260 km targeted in 2026, completion in 2028
- Barrier strip20 m-wide obstacles along the Belarus and Kaliningrad borders by end of 2028; bridges fitted for demolition
- Ottawa treaty withdrawalPoland effective February 20, 2026; Lithuania effective December 27, 2025
- Kapčiamiestis training groundApproved April 23, 2026; about 14,600 hectares next to the gap, exercises from 2028
- Brave Boar 2026June 16–26, 6,500 Polish troops with Lithuanian and French forces
- Evacuation plan, October 5, 2026About one million Baltic residents through the gap; Podlaskie prepared as a transit corridor
The gap over the years
- Oct 1920Poland and Lithuania sign the Suwałki Agreement in Suwałki on October 7. Two days later, Gen. Lucjan Żeligowski seizes Vilnius. The agreement never takes effect.
- 1945–1946Königsberg falls to the Red Army in April 1945. The Potsdam Agreement places it under Soviet control. It is renamed Kaliningrad on July 4, 1946.
- Mar 1990Lithuania restores its independence on March 11, 1990. It joins NATO on March 29, 2004, and the EU on May 1, 2004.
- Feb 2016The RAND Corporation publishes a wargame study finding that Russian forces could reach the outskirts of Tallinn or Riga within 36 to 60 hours.
- Sep 2025Russia and Belarus hold Zapad-2025 from September 12 to 16. Poland closes its border with Belarus from September 12 to 25. Days earlier, Russian drones enter Polish airspace.
- Oct 2026Poland and Lithuania announce an evacuation plan for about one million Baltic residents through the gap. Lithuania's parliament votes to remove the constitutional ban on nuclear weapons and foreign bases.
