New US defence secretary Pete Hegseth denied on Thursday that the Trump administration’s push for peace talks with Russia’s Vladimir Putin amounted to a “betrayal” of Ukraine. But the fact the question is even being posed tells its own story. Donald Trump’s call with Russia’s leader this week blindsided European capitals, and Volodymyr Zelenskyy, the Ukrainian leader and US ally. The president’s approach looks alarmingly like a path to the sellout his partners had feared. European leaders must use all means they can to try to talk Trump round to a more robust stance. But they must get their act together, too, in taking control of their own and Ukraine’s defence.

Trump’s 90-minute call to his Russian counterpart was a gift to the Kremlin. It ruptured a three-year effort to isolate a man who many European leaders, and former US president Joe Biden, have called a war criminal. Similarly welcome to Moscow, no doubt, were Hegseth’s comments that Ukrainian membership of Nato or restoring the country’s 2014 borders were unrealistic. These may reflect underlying truths. But ceding two key bargaining chips before negotiations even begin is an odd step for a US president who considers himself a master of the deal.

This raises the spectre of a “bad” peace that hands Moscow much of what it wants. The dangers are acute. It would risk destabilising Ukraine if its citizens and soldiers feel they are being forced into a capitulation. It would embolden Putin, and others, by suggesting military aggression brings rewards. Were the US to impose such a peace, over the heads of Kyiv and European capitals, and then walk away, the transatlantic alliance would be severely undermined — making Putin even more dangerous.