Russian President Vladimir Putin made a veiled threat to use nuclear weapons against Western states during a commemoration of Russia’s World War II victory in Moscow Thursday.

“Russia will do everything to prevent a global clash,” Putin said. “But at the same time, we will not allow anyone to threaten us.”

“Our strategic forces are always in a state of combat readiness,” the Russian leader added, referencing his country’s most powerful nuclear weapons. The comments came just days after Russia announced it would conduct military exercises to prepare for the use of “tactical” nuclear weapons, which are designed for attacks on soldiers rather than population centers.

The announcement set off alarm bells in Washington, which has sought to carefully avoid any escalation to a direct NATO-Russia war. The State Department called the move “reckless” but soothed some nerves by saying the U.S. did not anticipate any short-term use of nuclear weapons in Ukraine.

Putin’s latest moves are nonetheless part of a notable increase in Russian belligerence toward the West this past week, which Moscow claims is a response to Western efforts to rush weapons to Ukraine.

The situation increasingly resembles an escalation spiral, an international relations term for when two sides inch closer to direct war through gradual moves aimed at deterring the other party. As the war has dragged on, hawkish elements in the West and Russia have each succeeded in pressing their leaders to take steps that were once viewed as likely to result in further escalation.

Fearing a potential Ukrainian defeat, western Europe and the U.S. have increasingly signaled that the proverbial gloves are off. Britain recently declared that it had no issue with Ukraine using British weapons to strike Russian territory. “Just as Russia is striking inside Ukraine, you can quite understand why Ukraine feels the need to make sure it's defending itself,” British Foreign Minister David Cameron said last week.

And Cameron is right in a narrow, moral sense. But the practical wisdom of that greenlight is unclear given Russia’s predictable response, which was to threaten retaliation against U.K. military targets if any British weapons did indeed strike Russian territory.

Even if Britain had no intention of being dragged into the war, Russia’s threat took British views out of the picture entirely. It is now up to Ukraine — a country facing long odds in a desperate, defensive war — to decide whether it can stomach the risk of further escalation.

The U.S. is more attuned to the risks inherent to Britain’s approach. While Washington did quietly give Kyiv long-range missiles, the Biden administration also made clear that the weapons could only be used against targets inside of Ukrainian territory, a restriction aimed at threading the needle between Russia’s red lines and Ukraine’s needs.

French President Emmanuel Macron has been less careful. Macron responded to Ukraine’s battlefield struggles by suggesting that France could send its own troops into the fight, raising the specter of direct war between two nuclear-armed states.

In this case, Russia shot back at Macron by promising to attack any French troops that show up at the frontline. “If the French appear in the conflict zone, they will inevitably become targets for the Russian armed forces,” said a spokesperson for the Russian Foreign Ministry Wednesday.

From Russia’s perspective, all of these recent moves are likely about restoring deterrence. But that doesn’t make them any less terrifying to us in the West. And Russia feels the same when we respond to that fear with our own efforts to restore deterrence.

This should all serve as a reminder that the potential of a broader Russia-NATO war never went away. We’ve simply gotten used to living in a time of great danger. In practice, the chance of a cataclysmic mistake is growing more and more likely by the day.

In other diplomatic news:

— Following a meeting with Macron Monday, Chinese President Xi Jinping called for an international truce during the Olympic Games this summer, according to Politico. Macron thanked Xi for signing onto his idea of an Olympic truce and hinted that the pause could provide an opening to push for peace talks in Ukraine. “Maybe this could be an opportunity to work toward a sustainable resolution [of conflicts] in the full respect of international law,” the French leader said. Xi will have a chance to pitch the idea to Putin directly later this month when the Russian leader is scheduled to visit China.

— The only way to end the Ukraine war is through a temporary truce followed by peace talks, Italian Defense Minister Guido Crosetto said Monday, according to Reuters. Crosetto brushed off the idea that Putin hasn’t actually shown a desire to negotiate, saying “that is a good reason for us to try harder.” “We mustn’t give up any possible path of diplomacy, however narrow,” he argued, adding that Western sanctions and weapons had failed to deliver a decisive battlefield victory.

— Britain moved to expel Russia’s defense attache in London over allegations that the officer was using his military post for spying, according to AP News. The announcement came alongside new restrictions on diplomatic visas for future Russian envoys. Russia promised to respond “in kind.”

— Russian authorities arrested an American soldier in Vladivostok on charges of theft in early May, according to the New York Times. While U.S. officials have not formally designated the soldier as wrongfully detained, the arrest led to speculation that Russia is seeking further bargaining chips for prisoner swaps with the United States.

U.S. State Department news:

In a Wednesday press conference, State Department spokesperson Matthew Miller strongly discouraged Americans from traveling to Russia given the risk of wrongful arrest. “Russia has detained Americans for not legitimate law enforcement reasons but because it wants to hold them essentially as hostage,” Miller said. “Americans should not, for any reason, travel to Russia.