The great populist-insurgent of 100 years ago, one Vladimir Ilyich Ulyanov, found time while in cozy Zurich planning his Bolshevik revolution to pen an explanation for why things were “kicking off”, as we say these days: his book was entitled Imperialism, the Highest Stage of Capitalism or, in its French translation, the last stage. Were his modern successor (if political opposite) Donald Trump to follow suit in a tweet, he might substitute “globalism” for imperialism, adding “BAD, SICK! BUILD THAT WALL!” Marine Le Pen, France’s far-right presidential candidate, would surely agree.

One can imagine another author of a century ago, however, taking one glance at Trump and Le Pen and demanding that his publishers issue an updated version of his two-volume epic, The Decline of the West. Oswald Spengler saw the west less in the form of Nato, the US-Japan alliance and the European Union, which all define it for us today, and more as a European-American civilisation that was heading for history’s garbage-can — a verdict that even the coolest observation of the Trump administration’s opening weeks in office could now seem to confirm.

For this is the biggest issue of our times: a matter of whether, having seen so much failure in foreign affairs since 2001 and in economic affairs since 2008, the world’s richest, long most successful countries — i.e. the west — might now be slithering unstoppably down a slope, their slide likely to be accelerated by the populist-insurgents who are coming to power. Or, to put it a cheerier way, the issue is whether the Trumps and Le Pens of 2017 can be proved as wrong as were Lenin and Spengler a century ago.