Russia has told NATO in a written message that it would be ready to use its full arsenal, including nuclear weapons, if alliance members tried to isolate the Kaliningrad region from the rest of Russia. The Associated Press and Reuters both reported the warning, and Reuters said it had seen the document. NATO spokesperson Allison Hart confirmed that Russia had sent what she called a “non-paper,” an informal diplomatic text, and that the alliance had answered it, the Guardian (opens in new tab) reported.

Reuters quoted the document as saying: “Russia will be ready to use the entire arsenal of forces and capabilities at its disposal, including nuclear weapons, in order to defend its territory should NATO countries undertake any attempt aimed at isolating the Kaliningrad Region from the rest of the country.” According to Reuters, the text also accused NATO of a “dangerous and reckless course” and raised the possibility of “Russian strikes against decision-making centers in the alliance's member states right from the outset” if a conflict began.

The written message echoed statements issued this week by Russian embassies in Europe, the AP reported, and Reuters said embassies in at least three European countries had issued statements in the past three days. The AP said the embassies in the U.K. and Ireland posted their statements on Telegram and the embassy in Belgium gave its statement to the Russian state news agency TASS (opens in new tab). According to the AP, the embassies said Moscow had “information that NATO is preparing (an) air and naval blockade of Kaliningrad and Kaliningrad region.” The blockade claim comes from Russian officials. NATO and Lithuania reject it, as described below.

Hart said NATO’s reply noted “that NATO is a defensive alliance and none of our activities or exercises pose a risk to any part of Russia,” according to the AP. She added: “We strongly denounce the threat of force, including any irresponsible nuclear rhetoric.” Secretary General Mark Rutte told reporters, according to Reuters: “We are a defensive alliance. And stop the nuclear threats. This is absolutely not called for and not helpful.” When asked whether the nuclear risk to the Baltic states was real, Rutte said: “No, it's not. Putin knows that he can never win (against) NATO, so I don't take this that seriously.” TASS (opens in new tab) quoted Rutte as saying that he was not at liberty to disclose what Russia had sent.

Lithuania, which borders Kaliningrad, also rejected Moscow’s claims. Its Foreign Ministry told Fox News (opens in new tab): “Russia’s insinuations and threats have no basis. NATO is a defensive alliance and poses no threat to Russia or any other country.”

Kremlin spokesman Dmitry Peskov pointed to what he called “rampant statements” from Poland and other European countries about Kaliningrad, the AP reported. TASS (opens in new tab) reported that Peskov said Russia’s policy documents provide for a nuclear response to any attempt to blockade the region. Foreign Ministry spokeswoman Maria Zakharova said, according to Reuters, that some European figures “need to be brought back down to earth. We hope that our warnings will be heard by those to whom they are addressed.”

Kaliningrad lies between Poland and Lithuania. It is home to Russia’s main Baltic navy base and to nuclear-capable Iskander missiles, according to the AP, which also reported that NATO allies have more exercises planned in the Baltic region in October. A senior European defence official, whom Reuters did not name, said: “(This is the) first time since (the) Cold War that Russia is threatening us like this. So this is serious.” Fox News (opens in new tab) interviewed U.S. security analysts about the threat, and former Russian diplomat Nikolai Sokov told Reuters he saw a risk of mutual miscalculation.