Putin has been rattling the nuclear saber ever since the U.S. and its allies began arming Ukraine to defend itself against Russia’s unprovoked attack that started in February 2022. For more than a year now, Ukrainian President Volodmyr Zelensky has been asking President Biden and other Western leaders to allow Ukraine to use the weapons it has received to strike deep inside Russia. He argues, correctly, that the missile depots where Russia’s munitions are stored and the aircraft that Russia uses to bombard Ukrainian energy infrastructure and civilians should be legitimate targets. To his frustration, President Biden has thus far rebuffed his requests.

In recent months, increasing numbers of America’s allies have urged President Biden and German Chancellor Olaf Scholz, who also talks about avoiding escalation of the conflict, to lift the restrictions on Ukraine. High on President Zelensky’s list of priorities in his meetings with American and world leaders in Washington this week is said to be his quest for freedom to use the provided weapons in ways that he and his generals see fit. His argument has received broad bipartisan support in the U.S. Congress.

As Putin senses that the ground is shifting in the direction of allowing Ukraine to launch strikes deep inside Russia, he has resumed his nuclear saber rattling. Two days ago, he warned that Russia could use nuclear weapons if it was attacked with conventional armaments by any country. He stated: “It is proposed that aggression against Russia by any non-nuclear state, but with the participation or support of a nuclear state, be considered as their joint attack on the Russian Federation.” He added that “Moscow would consider [deploying nuclear weapons] if it detected the start of a massive launch of missiles, aircraft or drones against it.”

Practically, this purported update of Russia’s nuclear doctrine says nothing new. The current policy, issued in 2020, already states that “Russia may use nuclear weapons in case of a nuclear attack by an enemy or a conventional attack that threatens the existence of the state.” Ukraine has relentlessly launched swarms of drones against targets inside Russia for months, and made an incursion into Russia’s Kursk region, where it currently occupies a large patch of Russian land. Both are the sorts of conventional attacks referenced in the existing doctrine, but they have not been met with a nuclear response.

It is quite interesting to hear Putin say that he considers a non-nuclear state attacking Russia with the support of a nuclear state to be a trigger for Russian deployment of nuclear weapons. He pretends to be unaware of the thing called the Budapest Memorandum. That agreement explicitly states that in exchange for Ukraine giving up its nuclear weapons as part of the broader global nuclear non-proliferation effort, the U.S., the U.K., and by implication their allies, would come to the aid of Ukraine if its sovereignty and territorial integrity were ever threatened by Russia or another state. Someone should remind Putin that the support Ukraine is receiving from the U.S. and its NATO allies is exactly what the text of the Budapest Memorandum, which his country signed on to, prescribes.

Putin can choose to write his own history, or make up his own facts. And his acolytes and apologists can decide to believe him. But he shouldn’t expect the rest of us to swallow, without question, the falsehoods he peddles. The U.S. and its allies should not waver. They should earnestly honor the commitments they made to the Ukrainians when they pressured Ukraine’s leaders in the early 1990s to give up their country’s nuclear weapons and send them to, of all places, Russia.