President Vladimir Putin’s 2022 invasion of Ukraine has touched off the worst breakdown in relations between Russia and the West since the 1962 Cuban Missile Crisis, according to Russian and U.S. diplomats.

Just two days after U.S. lawmakers approved billions of dollars in additional military aid to Ukraine, Foreign Minister Sergei Lavrov said the United States and NATO were obsessed with the idea of inflicting “strategic defeat” on Russia.

Lavrov said Western support for Ukraine was putting the United States and its allies on the verge of a direct military clash with Russia.

“The Westerners are teetering dangerously on the brink of a direct military clash between nuclear powers, which is fraught with catastrophic consequences,” Lavrov told a Moscow conference on non-proliferation.

“Of particular concern is the fact that it is the ‘troika’ of Western nuclear states that are among the key sponsors of the criminal Kyiv regime, the main initiators of various provocative steps. We see serious strategic risks in this, leading to an increase in the level of nuclear danger.”

Since the war began, Russia has repeatedly warned of rising nuclear risks – warnings which the United States says it has to take seriously, though U.S. officials say they have seen no change in Russian nuclear posture.

Putin casts the war as part of a centuries-old battle with a decadent West which he says humiliated Russia after the Berlin Wall fell in 1989 by enlarging NATO and encroaching on what Moscow considers to be Russia’s historical sphere of influence.

Ukraine and its Western backers say the war is an imperial-style land grab by a corrupt dictatorship that will lead Russia into a strategic dead-end. Western leaders have vowed to work for a defeat of Russian forces in Ukraine, while ruling out any deployment of NATO personnel there.

HOT WAR?

As relations have deteriorated, Russia and the United States have both voiced regret about the disintegration of the web of arms-control treaties which sought to slow the Cold War arms race and reduce the risk of nuclear war.

Russia and the United States are by far the world’s biggest nuclear powers, holding more than 10,600 of the world’s 12,100 nuclear warheads. China has the third largest nuclear arsenal, followed by France and Britain.

Lavrov said that given the current crisis there was no basis for dialogue with the United States on arms control.

“In the context of an all-out hybrid war being waged against us, there is no basis for dialogue with the United States on arms control and strategic stability in general,” he said.

He accused the West of trying to impose restrictions on the nuclear arsenals of Russia and China while developing non-nuclear capabilities in an effort to achieve unilateral military superiority.

Lavrov said the West was building a global missile defence system which could decapitate a rival, basing nuclear weapons in Europe, basing medium- and shorter-range missiles in regions around the world and preparing to deploy weapons in space.

In February, Putin said Russia opposed the deployment of nuclear weapons in space, and his defence minister denied Washington’s accusations that Russia was developing a nuclear capability for space.

The United States says it is developing its defence capabilities in accordance with international agreements. It says it wants only the peaceful use of outer space and that its missile defence plans are defensive.

Lavrov also accused the West of waging a propaganda campaign to discredit Russia.

The West’s “goal is to divert attention of the international community from real threats in outer space, to achieve the allocation of additional financial resources to build up their national military space capabilities,” Lavrov said.

“Our priority remains the development of an international legally binding instrument that establishes reliable guarantees to prevent the deployment of weapons in outer space.”