There is so much this government doesn’t know. But two particular areas of ignorance exploded into view this week, allowing us to take a long, hard look at the cost they are inflicting on the country. Both are central to the Brexit project that remains this government’s defining mission – but only one of them is surprising.

Start with the unexpected ignorance, which is of the US and US politics. It’s a surprise, because if there’s one thing that unites the British political class it’s an interest in – even an obsessive fixation on – the politics of the United States. (And yes, I plead guilty.)If you were to hold a nerds’ convention on The West Wing or House of Cards, you’d host it in SW1. The Westminster villager who struggles to identify a single German politician besides Angela Merkel will speak with ease about the latest polling from Maine’s second congressional district or the precise composition of the Wisconsin supreme court.