London: Vladimir Putin keeps finding new ways to test Donald Trump and the major European leaders when they talk tough about the war in Ukraine.

That is because the Russian president pays no price for every escalation – and the latest provocation may be no different.

The American president is proving every day that he does not know how to respond to Putin. The European leaders are proving that they know what to say, but not what to do. So the provocations keep coming.

Donald Trump meets European leaders at the White House last month.Credit: Bloomberg

It is an extraordinary moment when Russian forces can fly drones into Polish airspace, mobilising NATO fighter jets and air defences in an emergency not seen since the Cold War, without any penalty.

Polish Prime Minister Donald Tusk makes a direct comparison to the years when Poland last suffered from a bellicose neighbour – when Germany invaded and triggered a world war.

“I have no reason to claim we’re on the brink of war, but a line has been crossed, and it’s incomparably more dangerous than before,” Tusk says. “This situation brings us the closest we have been to open conflict since World War II.”

Does that comparison hold? The passage of a drone fleet through the sky is........

© The Sydney Morning Herald