Trump the dealmaker will see politics as transactional and turn his talents to diplomacy, trying to rework Nato, say, or America’s poisonous relationship with Putin (“I think I’d be able to get along with him”) or with China, the last a relationship where trade disputes and great power rivalry could intersect in dangerous ways.

The greatest negotiators in the world are going to be busy, and if they apply the brinkmanship, bad faith and histrionics that typically come with big-ticket real estate transactions, the world will be in for sleepless nights, nights made more fraught still by Trump’s long-held belief that negotiation is a zero-sum game. There are only winners and losers, and Donald Trump is not a loser. 

But, for all this uncertainty, there are themes certain to be reflected in the policies that will be pursued by a Trump administration. Pre-eminent among them is his suspicion — shared by many Americans — that the US is being ripped off by its partners, whether in trade or in defence. As far back as 1987, Trump spent nearly $100,000 on full-page newspaper ads in which he maintained that Japan (then regarded as America’s main economic challenger) was free-riding off America’s willingness to pick up the tab for the country’s defence. He argued for a different approach: “Make Japan, Saudi Arabia, and others pay for the protection we extend our allies . . . ‘Tax’ these wealthy nations, not America . . . Let America’s economy grow unencumbered by the cost of defending those who can easily afford to pay us for the defence of their freedom. Let’s not let our great country be laughed at any more.” 

Nearly 30 years later, Trump was making a similar case to the New York Times (and not only the New York Times), except that the list of freeloaders now included most of Nato, run on a basis that he described as “unfair”, an adjective that, with its synonyms, has long been a bad, bad word in the Trump lexicon. In keeping with The Donald’s paranoid style, it hints at hostile conspiracy. Remember all that talk of a “rigged” election? But back to Nato: the US, Trump complained, was paying a “disproportionate share” of the freight.

He has a point. Currently America pays a little over 20 per cent of Nato’s direct costs, a number which is adjusted regularly and based on a percentage of its share of the alliance’s collective GNP. That seems reasonable enough (and, as these things go, the number is not huge), but the real problem concerns something far larger. The US effectively accounts for more than 70 per cent of all defence spending by Nato members. Some of that mismatch reflects the global reach of American power, not all of which is of much benefit to other Nato states either directly or indirectly, but even so.