Did the Russian Government meddle in the Brexit referendum, like it almost certainly meddled in the American presidential election? Interfering with democratic processes by the clandestine use of social media – the planting of tendentious advertising, fake news and so on – is an easy and cheap form of warfare by other means.

Donald Trump’s arrival in the White House certainly suited Moscow, and so does breaking open the European Union by the departure of one of its most important members. In each case, a shift of one or two percentage points could have made all the difference.