Hello from London,

Will conflict with Russia escalate? Vladimir Putin, again, wants to make you believe so. Joe Biden may be poised, at last, to say that Ukraine may use western-supplied weapons to hit military targets—such as airfields, logistics bases, or missile launchers—in Russian territory. That would be welcome, if overdue. Mr Putin, who booted out some British diplomats to show his anger on Friday, suggests this would be a step towards outright war between the West and Russia. His goal, of course, is to intimidate the West into inaction. But with bullies, caving into threats is a mistake. The West must dare to confront the aggressor. Ukraine, as the victim of aggression, has every right to fight back. Its allies should support it.

Russia continues to rain missiles, drones and artillery shells on Ukrainian cities and villages. Its forces are creeping towards making meaningful gains in the Donbas region of Ukraine. Across the country, Mr Putin’s goal is to destroy power supplies ahead of the winter, to further spread misery for ordinary people. Even as his forces commit war crimes, however, he has threatened Ukraine’s foreign supporters that they must not cross his red lines. At the same time, his forces continue to carry out sabotage and attempt assassinations in Europe, and to meddle in elections abroad, including in America.

Mr Putin’s threats of escalation, therefore, must be seen for what they are. He is aggressive when he observes weakness in others, not when he is met by strength. Some in the West were previously fearful about supplying battle tanks to Ukraine, and then F-16 fighter jets. As on those occasions, the lesson to take is that standing by the government in Kyiv, helping Ukraine to fend off its aggressor, is the right way to act.