The White House is aggressively seeking to weaken and dominate the United States’ traditional allies. European leaders must learn to fight back.

Sir Keir Starmer, Emmanuel Macron and Friedrich Merz have become adept at scrambling to deal with the latest bad news from Washington. Their meeting with Volodymyr Zelenskyy in Downing Street on Monday was so hastily arranged that Mr Macron needed to be back in Paris by late afternoon to meet Croatia’s prime minister, while Mr Merz was due on television for an end-of-year Q&A with the German public.

But diplomatic improvisation alone cannot fully answer Donald Trump’s structural threat to European security. The US president and his emissaries are trying to bully Mr Zelenskyy into an unjust peace deal that suits American and Russian interests. In response, the summit helped ramp up support for the use of up to £100bn in frozen Russian assets as collateral for a “reparations loan” to Ukraine. European counter-proposals for a ceasefire will need to be given the kind of financial backing that provides Mr Zelenskyy with leverage at a critical moment.