Companies weary of trying to keep supply chains clear and functioning in the face of the wave of protectionism triggered by the US administration might be forgiven for thinking that the world is already in the grip of a trade war. Yet could 2020 prove to be even worse than previous years?

In some areas, a precarious peace has been established. There are no certainties where US President Donald Trump is concerned, however, whether in trade or much else. This being a presidential election year, if Mr Trump thinks that a bout of trade conflict might bolster his image as an “America first” leader, he is capable of almost anything.

Trying to find a consistent rationale — hence a means of forecasting — for US actions on trade has proved impossible. Sometimes the president seems motivated by the need to make deals. Sometimes he seems to want conflict for its own sake. The political tension with Iran might distract him from starting fresh trade battles, or it might inspire him to go for confrontation on all fronts.