Donald Trump sold himself to the American electorate as a master dealmaker. In his previous career, as a real estate mogul in New York, he even shared his insights on negotiation in a book: The Art of the Deal. As Mr Trump explained: “My attitude is, you can’t get hurt by asking.”

The US president has several big foreign policy asks on the table: unilateral and complete denuclearisation by North Korea; Iran’s cessation of all uranium production and the granting of unqualified access to all nuclear sites; and $200bn of trade deficit-reducing agriculture and energy purchases by China. These are bold demands, but will he be hurt by asking?

The chances are that he will. Tough-talk and maximalist demands can work in a standalone business deal — when you are prepared to walk away, or have another potential business-partner. But it is more dangerous in international diplomacy, where you usually cannot choose who is sitting on the other side of the negotiating table. Nor can Mr Trump simply walk away from problems such as the North Korean and Iranian nuclear programmes.