(FINANCIAL TIMES) - Mr Greg Treverton used to be America's forecaster-in-chief. As chairman of the National Intelligence Council, he oversaw the US government's quadrennial Global Trends report. His 2017 report contained a cautious acknowledgement of America's own weaknesses. It noted "rising inequality" and "highly polarised politics". But the report concluded optimistically that America's "inclusive ideal remains a critical advantage".

Four years on, Mr Treverton, now in academia, takes a dramatically more pessimistic view. Last week, he published an article, co-written with Ms Karen Treverton, headlined Civil War Is Coming. It argues that the divisions between red and blue America are now so extreme that some sort of split is inevitable.