Donald Trump’s worldview is zero-sum. He thinks that if he gains, someone else must lose. It is how he sees world trade: other countries, mainly China, are taking advantage of America. Therefore the solution is to impose tariffs on Chinese imports to the US, so that China loses and the US gains.
But it is also how he sees Britain, and the rest of Europe. Hence the comment from Stephen Moore, the president-elect’s adviser, who seems to have reflected Trump’s thinking when he said: “Britain has to decide – do you want to go towards the European socialist model or do you want to go towards the US free market?”