The US security strategy falls short, but not for the reasons cited by Trump critics

As 2017 draws to a close, the world has seldom been so binary. You love Donald Trump or you loathe him. You adore Brexit or abhor it. This polarisation has been fostered by giant online social networks and the phenomenon students of networks know as “homophily”: birds of a feather flock together.

Facebook encourages you to like or not like what you see in your news feed. Twitter allows you to retweet or like other people’s tweets or block users who offend your sensibilities. Pretty soon you are in a filter bubble with people who share your view of the world. The result is paradise not just for fake news but extreme views.

In the wake of the exposure of Harvey Weinstein, shrill voices insist all men are potential rapists. Since the death of a (white) protester in Charlottesville, Virginia, zealots insist all white people are racists. White men must therefore be racist rapists.

I have had a tough time this year explaining even to friends why I like some aspects of the Trump administration while disliking others. And I wish I’d had a bitcoin for each time someone complained that my position on Brexit has flip-flopped; I’m just ambivalent.

I had a great deal of sympathy last year with those who expressed dissatisfaction with the status quo by voting for Brexit or Trump. But I was also aware there would be significant difficulties with both these populist ventures, as has proven the case. This used to be known, in a bygone era, as nuance.