Russia ramps up nuclear threats against West

Russia sent shock waves of unease across Europe on Tuesday, the fourth anniversary of its invasion of Ukraine, by pushing an unverified claim that Britain and France are working to provide a nuclear weapon to Kyiv and by threatening Russian nuclear strikes against all three as retaliation.

The allegation and threats, leveled by senior security official Dmitry Medvedev, were quickly rebuked and denied by officials in London and Paris who called the development an example of Russian “disinformation.” Ukraine characterized Moscow’s posturing as “absurd.”

Meanwhile, the Trump administration is attempting to breathe life into peace negotiations between Moscow and Kyiv.

Multiple rounds of talks over the past months have become snarled by a diplomatic impasse over the Donbas, eastern Ukraine’s industrial heartland. Although Russian military forces occupy significant stretches of the territory, they have failed to totally control it.

Kremlin spokesperson Dmitry Peskov said Tuesday that Moscow is “open” to pursuing a diplomatic end to the war but stressed that the Ukraine invasion will continue in pursuit of Moscow’s goals. They include a demand that Ukraine renounce its bid to join NATO, sharply cut its army and cede vast swaths of territory.

The Ukrainian Foreign Ministry said in a statement that Russia has imperial ambitions, aiming to destabilize and weaken European countries and undermine multilateral cooperation among democratic states. “By refusing to end the war in Ukraine, Russia is destroying the very architecture of European and global security, strategic stability, and the nuclear non-proliferation regime,” the ministry said.

Ukrainian President Volodymyr Zelenskyy marked the anniversary of the invasion by declaring in a social media post that Russian President Vladimir Putin “has not broken Ukrainians.”

“He has not won this war,” Mr. Zelenskyy said.

Nuclear threats

Russian officials, including Mr. Putin, have repeatedly issued veiled threats to use tactical nuclear weapons as a way to deter NATO military support for Ukraine over the past four years.

Mr. Putin put the world on edge in May by asserting that he hoped the need to use nuclear weapons in Ukraine would not arise.

The fresh threats from Mr. Medvedev, a Putin underling who served as Russia’s president from 2008 to 2012 and is now deputy chairman of Mr. Putin’s security council, were more specific, but they appeared driven by the same desire to shake Western resolve at a critical moment as the war churns into its fifth year.

Early Tuesday, Russia’s state-owned Tass news agency carried a report claiming the Russian Foreign Intelligence Service had determined that Britain and France had developed plans to provide Kyiv with nuclear firepower. The spy agency, known as the SVR, said government officials in London and Paris are weighing the move because Ukraine’s position in the war and in negotiations to end the conflict has become untenable.

“Kyiv would be able to aspire to more advantageous terms of ceasing the hostilities if it possessed a nuclear [weapon] or at least a so-called ‘dirty bomb,’” the SVR said. “London and Paris are actively working over the issue of providing Kyiv with a weapon of this kind, as well as with means of its delivery.”

A dirty bomb is a makeshift nuclear weapon that combines conventional explosives such as dynamite with radioactive material with the goal of spreading radiation over a target area upon detonation.

Britain, France and Russia are all signatories to the Treaty on the Non-Proliferation of Nuclear Weapons, under which countries with nuclear weapons are prevented from transferring them to any non-nuclear-armed state. Ukraine relinquished its Soviet-era nuclear arsenal in the 1990s as part of the Budapest Memorandum and is not a nuclear-armed state.

The Russian SVR claimed that a potential British-French operation would involve the covert transfer to Ukraine of relevant European-made components, equipment and technology for a dirty bomb and that Germany “has prudently refused to take part in this dangerous venture.”

The French navy operates four nuclear-powered ballistic missile submarines, considered the backbone of the country’s nuclear deterrent.

The Russian SVR said France and Britain are considering providing Ukraine with a warhead from one of the missiles.

“The Westeners’ main efforts are focused on making Kyiv’s possession of nuclear weapons look like it was developed by Ukrainians themselves,” the agency said.

Pushback from Europe

The Kremlin provided no public evidence to back up the SVR claims.

Mr. Medvedev made global headlines later Tuesday by asserting that Russia could be forced to use tactical nuclear weapons against Ukraine, and potentially Britain and France, if nuclear technology is transferred to Kyiv.

“This is a direct transfer of nuclear weapons to a country at war,” said Mr. Medvedev, according to Tass. “Russia would have to use all weapons, including nonstrategic nuclear ones, to strike targets in Ukraine that pose a threat to our country and, if necessary, in the supplying countries as well.”

Mr. Medvedev was once considered a relatively liberal technocrat inside the Kremlin, but he has emerged as one of the most heated critics of the West since Russia’s invasion of Ukraine. He said targeting Britain and France, along with Ukraine, would be a “proportional response” to supplying Kyiv with an atomic weapon.

“Information about France and Britain’s intention to transfer nuclear technology to the Kyiv Nazi regime radically changes the situation,” Mr. Medvedev wrote on Telegram.

The response from Paris, London and Kyiv was swift.

A spokesperson for British Prime Minister Keir Starmer said the Kremlin’s claims were a “clear attempt” by Moscow to distract from the Russian military’s poor performance on the battlefield.

“There is no truth to this,” the spokesperson said in a statement. “We will continue with our efforts to secure a just and lasting peace.”

Heorhii Tykhyi, a spokesperson for the Ukrainian Foreign Ministry, told Reuters that “Russian officials, known for their impressive record of lies, are once again trying to fabricate the old ‘dirty bomb’ nonsense.”

An X account linked to the French Foreign Ministry and designed to tackle misinformation also dismissed the Russian claims, according to Euronews, a prominent European television news network.

“Nuclear brinkmanship won’t hide the overwhelming international support for Ukraine on the fourth anniversary of [Russia’s] failed ‘three-day war,’” the account said in a post.

French Foreign Ministry officials wrote that “when the whole world sees the truth — [Russian] soldiers dying for nothing, your economy collapsing, your population sealed in a digital ghetto — all that’s left is noise, threats, and empty words. Russia is losing.”

• This article is based in part on wire service reports.