On Friday, June 17, Lithuanian Railways announced that it would no longer allow the transit of steel and iron to the Russian exclave of Kaliningrad, enforcing European Union sanctions that entered into effect. Unsurprisingly, the Russian government warned that it would retaliate against the ban.

 

It all started unremarkably. LTG, the state-owned railway company of Lithuania, informed its clients of the measure. Panic-hoarding in Kaliningrad and fury in the Kremlin ensued.

 

Yet another ramification of the Russian invasion of Ukraine, this instance of bureaucratic procedure by a railway operator in a Baltic country can be the trigger for potentially catastrophic consequences. The reason is the Suwałki Gap, a 40-mile (65-kilometer) long stretch of land that connects mainland Russia by way of Belarus to Kaliningrad through the Lithuanian-Polish border.

 

And it is on this corridor where NATO troops and the Russian forces are at their closest, for Kaliningrad is heavily militarized and it is where Russia’s Baltic fleet is headquartered. NATO forces are deployed on both sides of the gap.

 

A legacy of World War Two, when the Soviet Union annexed Koenigsberg from Germany, renamed it and repopulated it with Russians, the gap was strategically irrelevant for as long as the communist bloc lasted. With the Soviet collapse, followed by Poland and the Baltic republics—Lithuania, Latvia, and Estonia—joining NATO, the Suwałki Gap became the weakest link of the Atlantic alliance. Russia would only need to capture it to encircle the Baltic trio: this was a scenario contemplated in the joint Russian-Belarussian war games of 2017 and 2021. That equation would change should Sweden and Finland finally join NATO, as Russia would be effectively blocked on the Baltic Sea.

 

Even worse still, however, Russia’s nuclear doctrine is poorly understood. Much of what is superficially seen as erratic in President Vladimir Putin’s threats about the use of nuclear weapons in the conflict is backed up by Soviet and thereafter Russian military doctrine.

 

In Soviet times, a limited use of both strategic and tactical nuclear weapons to de-escalate a conflict in the Baltic region was considered theoretically possible, as Lukas Milevski says in The West’s East: Contemporary Baltic Defense in Strategic Perspective (2018). In the late 1990s, Russia revived an updated version of this doctrine that contemplated “employing nuclear forces in a local or regional war”. This scenario involved “using strategic nuclear forces and operational-tactical nuclear weapons within a theatre of military operations”.

 

Hence, there is more to the nuclear menace in the Ukraine conflict than Putin’s bravado.

 

With the Suwałki Gap, dilemmas that had been put to rest for generations are returning to the fore in Europe a century after the nightmare scenarios posed by the Danzig Corridor in the 1920s-1930s. Every possible solution to it only compounded the intractable problems they were supposed to address, until an untenable geography became the trigger for World War Two.

 

Herein lie the dangers of the decision taken by Lithuania’s state railways operator to adhere strictly to the letter of the EU sanctions. No matter how big or small these little actions, they may unleash a domino effect with unpredictable consequences. It really does not matter that much that the Suwałki Gap is such a perilously thin line separating Russian and NATO forces. Why should it? The firepower both camps boast overrides the importance of any borders.

 

Until an endgame for the Ukraine war becomes clear, we will be walking on eggshells. Anything can light the fuse of a much larger conflict. More like World War One, a decision by Lithuanian Railways—or a stray Russian missile that crosses into Poland, or any other incident—can start a chain reaction like the bullet shot by Gavrilo Princip on June 28, 1914, in Sarajevo.