For all Donald Trump’s bluster about restoring American strength, his attempt to bully European allies over Greenland reveals a deeper weakness: coercive diplomacy only works if people are afraid to resist. Increasingly, they aren’t. And that is a good thing. Bullies often back down when confronted – their power relies on fear. Mr Trump’s threat to impose sweeping tariffs on Europeans unless they acquiesce to his demand to “purchase” Greenland has stripped his trade policy bare. This is not about economic security, unfair trade or protecting American workers. It is about using tariffs as a weapon to force nations to submit.

The response from Europe has been united and swift. That in itself should send a message. France’s Emmanuel Macron says plainly “no amount of intimidation” will alter Europe’s position. Denmark has anchored the issue firmly inside Nato’s collective security. EU leaders have warned that tariff threats risk a dangerous downward spiral. Even Italy’s prime minister, Giorgia Meloni, seen as ideologically close to Mr Trump, publicly called the tariff threat a “mistake” – adding that she has told him so.

What Mr Trump did not reckon with was that intimidating Europe would carry institutional consequences. The European parliament is now moving to pause ratification of the EU-US trade deal that European leaders were pressured by the US to accept last summer. The three largest parliamentary blocs in Strasbourg – conservatives, social democrats and liberals – are marching together. In Brussels, this is not theatre. The EU runs trade policy, not individual capitals, as Britain found out during Brexit. Mr Trump can threaten governments; he cannot browbeat European institutions designed to withstand coercion.

The UK is speaking up. Though outside the EU, the country issued ajoint statement with allies saying that Mr Trump’s threat risks a “dangerous downward spiral” and “undermines transatlantic relations”. On his own Sir Keir Starmer was reduced to pleading for better behaviour. Britain is like Greece to America’s Rome – with the added trauma of having once been Rome itself.

But there are signs of a rules-based system being built without the US. Canada, one of America’s closest allies, is hedging its bets. The country’s trade deal with Beijing shows how middle powers shift when Washington becomes erratic. Diversifying away from Mr Trump’s America is the right route to take. The US president ought to drop his tough talk and get on with bolstering Greenland’s defences and, if necessary, building proper commercial partnerships that benefit both the US and the island’s population.

Some point to Richard Nixon’s “madman theory” as a historical precedent. But there is a difference between unpredictability that creates leverage and recklessness that destroys trust. Nixon shocked the system in 1971 because the system was coming apart. Today we have disorder, but Mr Trump shocks the system because he seems to enjoy the spectacle. That matters because coercive foreign policy requires domestic legitimacy. Polling shows a majority of Americans think Mr Trump’s presidency a failure. A president who lacks consent at home cannot credibly demand submission abroad. What he projects instead is desperation. Mr Trump believes influence comes through ultimatums and coercion. But power, in the real world, rests on trust, predictability and persuading others to follow. Yet allies are pushing back. The more Mr Trump resorts to bullying, the more the world will learn how to live without him.