Russian President Vladimir Putin warned the West on Tuesday that NATO members in Europe were playing with fire by proposing to let Ukraine use Western weapons to strike inside Russia, which he said could trigger a global conflict.
More than two years into the deadliest land war in Europe since World War Two, as the West considers what to do about Russian military advances, Putin is increasingly evoking the risk of a global war, while Western leaders play it down.
NATO Secretary General Jens Stoltenberg told the Economist that alliance members should let Ukraine strike deep into Russia with Western weapons, a view supported by some European members of the transatlantic alliance but not the United States.
Russian forces have advanced into Ukraine's Kharkiv province safe in the knowledge that Ukraine cannot attack missile launchers being fired deep inside Russia because it cannot use the Western missiles that have the required range.
Meanwhile, Western-made air defenses cannot attempt to down Russian rockets until they cross the Ukrainian border, only 25 km (15 miles) or so from Ukraine's second city, Kharkiv.
"Constant escalation can lead to serious consequences," Putin told reporters in Tashkent in Uzbekistan.
"If these serious consequences occur in Europe, how will the United States behave, bearing in mind our parity in the field of strategic weapons?"
"It's hard to say - do they want a global conflict?"
Putin said Ukrainian strikes with long-range weapons would need Western satellite, intelligence and military help - so the West would have to be directly involved in such attacks.
He said sending French troops to Ukraine would also be a step towards global conflict and that smaller countries considering deeper involvement "should be aware of what they are playing with" as they had small land areas and dense populations.
"This is a factor that they should keep in mind before talking about striking deep into Russian territory. This is a serious thing, and we are of course watching it very closely," Putin said.
RUSSIAN ADVANCES TRIGGER DEBATE IN WEST
Russia's full-scale invasion of Ukraine in 2022 touched off the worst breakdown in relations with the West for 60 years.
The invasion has caused the deaths of tens of thousands of Ukrainian civilians, driven millions to flee abroad, and reduced neighborhoods and whole cities to rubble.
Putin casts the war as part of a struggle with the West, which he says is exploiting Ukraine as part of a wider plan to encroach on what he considers Moscow's sphere of influence.
The West and Ukraine cast the attack as a simple land grab: Russia controls 18% of Ukraine, and the crisis is now escalating into what diplomats say is its most dangerous phase.
Russian officials say Moscow's patience is wearing thin after Ukrainian attacks on Russian cities, oil refineries and elements of its nuclear early-warning system.
Putin said Kyiv and its Western backers had provoked Russia's offensive on the Kharkiv region by ignoring repeated warnings not to let Ukraine attack the adjacent Russian region of Belgorod.