Russia’s warning that it could use nuclear weapons if NATO seeks to cut off Kaliningrad from the rest of the country has intensified concerns that the heavily militarized Baltic exclave could become a dangerous flashpoint between Moscow and the alliance. Experts also say Russia is already using the territory as a base for hybrid warfare aimed at pressuring Europe.
In a diplomatic document, Moscow told NATO it was prepared to deploy “the entire arsenal of forces and capabilities at its disposal, including nuclear weapons,” if alliance members tried to isolate Kaliningrad, Reuters reported Wednesday.
Kaliningrad is a Russian territory separated from the country’s mainland. Located on the Baltic Sea between NATO members Poland and Lithuania, it houses major Russian military assets, including elements of the Baltic Fleet.
Russian President Vladimir Putin looks on a map showing the Kaliningrad exclave and the rest of Russia, Sept. 10, 2006. (Konstantin Zavrazhin/Gamma-Rapho via Getty Images)
The Russian document also warned that strikes against “decision-making centers” in NATO countries could be launched at the beginning of a conflict.
NATO rejected Moscow’s accusations in a response reviewed by News Outlet, emphasizing that the alliance is defensive and that its exercises and other activities do not threaten Russian territory. NATO also called on Russia to end its “irresponsible nuclear rhetoric.”
Carrie Filipetti, executive director of the Vandenberg Coalition, a nonpartisan network of foreign policy leaders, said Moscow has repeatedly used nuclear threats in an effort to discourage Western backing for Ukraine.
“Russia has threatened to use nuclear weapons in the past, including veiled references to tactical nuclear attacks at the beginning of Putin’s invasion of Ukraine, lowering their formal threshold for launching a nuclear attack in 2024, placing Russia’s nuclear forces on high alert, and restarting nuclear testing,” Filipetti told News Outlet. “It is very common for Putin to use these threats, because he sees it as a way to deter Europe and the United States from continuing to support Ukraine.”
The Blue Ridge-class command and control ship USS Mount Whitney participates in exercise Baltic Operations 2025 as ships sail in formation through the Baltic Sea, June 5, 2025. (U.S. Navy Courtesy Photo)
Filipetti said the warning over a possible nuclear response to any threat or isolation of Kaliningrad follows several recent developments, including NATO aircraft being scrambled in response to Russian planes, U.S. and NATO air exercises near the exclave last month, and rising tensions linked to the war in Ukraine.
Filipetti, a former deputy assistant secretary at the State Department and senior policy adviser for the United States Mission to the United Nations, said the timing also reflects growing pressure on Moscow as the conflict continues.
“Putin seems to understand that the tide is turning against him, and he’s resorting to aggressive rhetoric to try to stop European support for Ukraine as he has tried to do in the past,” she said.
Dr. Azeem Ibrahim, a research professor at the Strategic Studies Institute at the U.S. Army War College and chief strategy officer at the New Lines Institute, said NATO should treat the warning seriously. He pointed to Kaliningrad’s wider role in Russia’s confrontation with Europe.
NATO’s largest annual maritime drill, Exercise Dynamic Mariner/Flotex 25, continues in the Gulf of Cadiz off southern Spain on March 28, 2025. (Burak Akbulut/Anadolu via Getty Images)
Ibrahim said NATO has traditionally focused on the prospect of conventional warfare involving “tanks and troops and divisions.” Russia, however, is increasingly relying on tactics intended to disrupt the infrastructure and systems that civilian life depends on.
“Russia is actually adopting a very different approach,” he said, describing a hybrid warfare strategy aimed at “infrastructure” and “societies in general — what keeps societies functioning.”
Ibrahim characterized Kaliningrad as the “front line” of that campaign.
“It’s essentially become a Russian fortress,” he said. “This is essentially a front-line operation of the Russians in terms of signals intelligence, signals interference and essentially mechanisms by which to carry out this hybrid warfare.”
According to Ibrahim, such interference could form part of a wider confrontation by disrupting civilian communications and critical infrastructure before or alongside a conventional military assault.
“All of that would be preceded by interference operations like this to ensure that societies are not functioning, are not able to respond to emergency services, the news information services, etc.,” Ibrahim said. “So governments lose control over what actually makes societies function.”
Soldiers from Poland’s 18th Division demonstrate battlefield medical training near the Belarus border after a serviceman from the division was killed in an attack by an illegal migrant. May 16, 2026. (Efrat Lachter/News Outlet)
The challenge for NATO, he said, is that such operations can be more difficult to attribute than a conventional assault.
“Many times, you cannot trace exactly where a lot of this interference is actually coming from — attacks on power stations or internet and telecommunications, et cetera,” Ibrahim said. “There’s always some sort of plausible deniability if it’s done by an actor who’s very capable.”
The ambiguity, Ibrahim argued, presents a challenge for an alliance built around collective defense against armed attack.
“NATO really does have to kind of reconfigure its posture to understand that these kinds of attacks are equivalent to essentially any sort of kinetic attack,” he said.
Asked what NATO and neighboring Poland and Lithuania should do following Russia’s warning, Ibrahim called for the alliance to establish clearer consequences for hybrid attacks.
“We now need to start going on the offensive in terms of hybrid warfare and understanding the threat and pushing back and sending a very clear signal to Moscow that such threats will not stand,” he said, arguing that a sufficiently serious hybrid attack should be considered capable of triggering NATO’s Article 5 collective-defense clause.
Lithuania, which directly borders Kaliningrad, rejected Moscow’s warning and accused Russia of trying to undermine NATO unity and Western support for Ukraine.
“Russia’s insinuations and threats have no basis. NATO is a defensive alliance and poses no threat to Russia or any other country,” Lithuania’s Foreign Ministry told News Outlet. “Russia’s threatening is intended to fracture transatlantic unity and impede our support to Ukraine. Russia will not achieve its goals.”
The ministry added: “We strongly condemn any threats to use force and irresponsible nuclear rhetoric. Russia must stop its aggression against Ukraine… Lithuania is strengthening its national defense system and capabilities, including air defense,” the ministry said. “We train with our allies and work alongside NATO forces deployed in Lithuania. We are prepared to defend every inch of NATO territory and respond to any threats.”
The ministry said Lithuania would also continue providing “comprehensive support to Ukraine and its fight against the aggressor Russia.”
Retired Air Force Lt. Gen. Richard Newton told News Outlet, “In the weeks leading up to February 2022, many officials and commentators (myself included) weren’t sure Putin would actually invade Ukraine, even though there were a number of warnings and indicators he would do so. And then on that Feb. 24, Putin launched the largest land invasion against Ukraine since World War II.”
A razor-wire boundary fence along the Polish-Lithuanian border with the Russian exclave of Kaliningrad, near the Suwalki Gap on Sept. 26, 2026. The gap is a 104-kilometre stretch of the Polish-Lithuanian border that forms the only land corridor connecting the Baltic states with the rest of NATO, while separating Belarus from Russia’s Kaliningrad exclave. (Sergei Gapon/AFP via Getty Images)
“NATO should take Russia’s warning seriously that it could resort to employing nuclear weapons against the alliance should Kaliningrad be cut off from Russia. We are in the midst of Russia employing ‘gray zone’ coercive actions against NATO nations, so this pronouncement should not surprise the West,” he added.
Filipetti cautioned that regardless of whether Moscow intends to follow through, nuclear threats themselves carry risks.
“NATO is a defensive organization that is in no way threatening Russia’s position on Kaliningrad,” she said. “That said, any time there is a public threat of nuclear attack it must be taken seriously, especially with someone like Putin.”
“Nuclear bombs are a potentially world-altering technology,” Filipetti added. “It is not only their use, but the threat of their use, that could cause significant miscalculations and escalations.”
Russia has denied Western accusations that it is conducting hybrid warfare against European states and has said it has no intention of attacking NATO countries. Moscow says NATO military activity around Kaliningrad is instead contributing to an increasingly dangerous confrontation.
Kremlin spokesman Dmitry Peskov characterized recent Russian warnings as diplomatic reminders to “hotheads in Europe,” Reuters reported Wednesday.
An office building burns following a Russian drone attack in central Odesa, Ukraine, on Sept. 18, 2026. (Michael Shtekel/AP)
News Outlet reached out to the Polish and Russian embassies for comment but did not receive responses in time for publication.
Reuters contributed to this story.
