Russia warns NATO of potential nuclear response over Kaliningrad as alliance rejects threats

Diplomatic warning delivered to Brussels

The Russian government sent an informal diplomatic document, known as a non-paper, to NATO headquarters and the Belgian foreign ministry through its embassy in Brussels. The text asserted that Moscow is prepared to use its entire military arsenal, including nuclear weapons, to defend its territory if NATO member states attempt to cut off or isolate the Kaliningrad region. Russian officials also stated in the text that potential responses could include direct strikes against decision-making centres in NATO member countries from the very start of any direct armed conflict. In addition to the private non-paper, Russian embassies in at least three European nations released formal statements over a three-day span, claiming alliance military exercises around the exclave create high risks of military confrontation. Russian diplomats denied preparing any offensive action against European neighbours while warning that any aggression directed at Kaliningrad would trigger severe defensive countermeasures.

NATO response and alliance posture

NATO leadership confirmed receipt of the Russian diplomatic document and delivered an official reply rejecting the accusations. Alliance officials maintained that collective exercises are defensive in nature and do not threaten any portion of Russian territory. Spokesperson Allison Hart presented the alliance position following the transmission of the reply.

We have sent a response, noting that NATO is a defensive Alliance and none of our activities or exercises pose a risk to any part of Russia. We strongly denounce the threat of force, including any irresponsible nuclear rhetoric. We call on Russia to end its unprovoked war in Ukraine.

A senior European defence official noted that the explicit nature of the communication represents a level of threat not seen between Moscow and Western capitals since the Cold War.

Strategic geography of the Baltic exclave

The Kaliningrad region is a heavily militarised Russian territory situated on the Baltic Sea coast, geographically separated from mainland Russia and bordered by NATO members Poland and Lithuania. Moscow pointed to military drills conducted by allied forces in surrounding territories, including Poland, Lithuania, and Latvia, as the source of escalating friction. Russian diplomatic communications called on NATO members to cease military activity in the Baltic perimeter to prevent wider escalation. Western governments have rejected claims of aggressive planning, pointing to concerns over Russian hybrid operations, including incidents of suspected sabotage and arson reported across European states.

Widening diplomatic friction

The delivery of the warning coincided with broader geopolitical friction between Moscow and European capitals. Russian Foreign Minister Sergei Lavrov stated that European nations are already in a state of conflict with Russia, pointing to Western military backing for Ukraine. Meanwhile, European security authorities continue investigating incidents within their borders, including a sabotage case in Tallinn attributed by Estonian authorities to Russian intelligence services. In draft budgetary figures for 2027, Moscow projected national defence spending to reach 17,100 billion rubles, representing a 27% increase compared to the initial 2026 allocation, while reducing allocations for social welfare, healthcare, and education.