The true danger posed by Donald Trump

That should be a relief to America’s allies everywhere. A crisis that threatened to engulf the transatlantic alliance has eased. But for how long? This may be only a tactical retreat. Mr Trump has coveted Greenland for years. In setting out his claim he spoke about NATO with a contempt that should put the capitals of Europe on high alert.

The Greenland crisis holds lessons for all countries. One is that Mr Trump will buckle under pressure, without necessarily surrendering his long-term goals. Another is that the president’s narrow, pessimistic view of the world and his willingness to rewrite history has eroded the trust which used to underpin America’s alliances. Last, it follows that every falling-out under Mr Trump threatens to be existential. He portends a global realignment for which America’s allies must prepare.

With Greenland, Europe was lucky. It got through this round because Mr Trump chose to pick a fight over a prize of almost no strategic value to America. Mr Trump argues, correctly, that the Arctic will be contested as its melting ice admits the world’s navies. Greenland is a site for early-warning stations that protect America from attack, he says. If the island belongs to America, neither Russia nor China will dare strike it.

But Greenland already has an American base and is protected by NATO’s Article 5, under which its members, including the United States, pledge to come to the aid of any state that is attacked. America can do pretty much what it wants in Greenland under today’s treaties and Denmark has offered to strengthen them further. The extra benefit of being able to colour in the map is nugatory.

All this helped Europeans explain that the potential cost to America was not worth it. Mr Trump’s bluster about levying tariffs led some European countries to threaten retaliation. The markets took note of the harm a trade war and a security crisis could inflict on America. Public opinion there is broadly against a costly takeover. Under fierce European lobbying, Congress showed rare signs of resisting Mr Trump.

The moral is that, to get America’s president to retreat, you have to convince him that you will impose a price on him. In most of their dealings with Mr Trump, European leaders have treated him with sycophancy truffled by the odd, muted objection. This time, they were more assertive and it worked.

That is where the good news ends. At Davos Mr Trump talked about owning Greenland—which means that he could yet seek leverage by reviving tariffs or even the threat to use force. Even if he doesn’t and America and Denmark successfully negotiate a revised treaty that falls short of sovereignty, Europeans should pay heed to the language in his speech. That is because it betrayed his contempt for Europe and for the value to America of the transatlantic alliance as it works today.

Mr Trump said America has paid “100%" for NATO and never got anything in return. Scott Bessent, his treasury secretary, gripes that America has spent $22trn more than freeloading Europeans on defence since 1980. The administration’s security strategy warned that Europe faces “civilisational erasure" from immigration and may soon no longer be a reliable ally.

That is a travesty of NATO’s history and Europe’s future. It is true that, since the end of the cold war, the alliance’s European members have spent too little on defence. But during it, they were a bulwark against Soviet expansion which was built on shared values. In any case, they are beginning to spend more again, partly because of Mr Trump’s hectoring, but also because of the growing threat from Russia.

NATO has succeeded because it was founded on mutual benefit. The only occasion in which Article 5 has been invoked was after America was attacked on 9/11. Proportionally, Denmark lost more troops in Afghanistan than America did. Europe provides America with bases, such as Ramstein in Germany, that enable America to project power around the world; it defends American interests, including in the Arctic.

Unfortunately, Mr Trump is unlikely to change his view that allies are spongers and shared values are for suckers. That is sure to lead to further confrontations, whether over Greenland or something else. America’s friends, in Europe and beyond, therefore need to prepare for a world in which they are alone. That starts by preserving as much of NATO as they can. Building hard power takes years, and Mr Trump is in a hurry.

The problem is that Mr Trump believes that America holds all the cards, because his European and Asian allies have more to lose from a rift than America does. He is partly right. For example, if America refused to sell Ukraine weapons and blocked intelligence, it would hasten a Ukrainian defeat and the next Russian aggression. Europe and Asia depend on America for military equipment. For instance, America provides 40% of NATO’s capacity—and it is the most important 40%. America supplies Europe with vital services and digital technologies.

Europe should try to expose the shallowness of that thinking. It can start by setting out an inventory of what America stands to lose—and it includes a lot more than the bill to American consumers of more tariffs. Europe is a market for $1trn-worth of American goods and services. It supplies essential technologies, including for chipmaking, telecoms equipment, lenses, aircraft and much more. European spies, especially Britain’s, give America valuable intelligence.

Greenland is just the tip of the iceberg

Next, Europe should warn Americans about the hostile world Mr Trump is willing into existence. Unable to trust America, Germany, Japan, Poland and South Korea would rearm even faster and perhaps seek nuclear weapons. China and Russia will not agree with Mr Trump on where America’s influence ends and theirs begins. Proliferation would curb the value of America’s own arsenal and inhibit its statecraft. All this might lead to a war so devastating that America could not stay out.

Europe needs to ensure that, when investors, voters and Congress react to Mr Trump’s vainglorious schemes, they focus not just on Europe’s vulnerabilities but also on the harm that they themselves could suffer. Investors do not want to lose money, citizens do not want to scrimp and save and politicians do not want to be voted out.

Unfortunately, America’s alliances cannot survive continual bouts of arm-wrestling brought about by a president who thinks allies have no value. From within, Europe will suffer disunity, as different countries seek varying accommodations with a predatory America. From without, the presidents of Russia and China, Vladimir Putin and Xi Jinping, will seek to corrode the allies’ unity with provocations that divide them.

In the past decades the reassurance of American protection has coddled Europeans. Rather than deal with hard power, they have focused on the good life. Those times are over. European leaders should strive to slow down the erosion of the transatlantic alliance, but they must also prepare for the day when NATO is no more.