When Vladimir Putin sent his troops into Ukraine, says Yuval Noah Harari in The Atlantic, he ended “the most peaceful era in human history”. Until the late 20th century, the word “peace” meant merely “the temporary absence of war” – conflict was always just round the corner. Military spending dominated the budget of “every empire, sultanate, kingdom and republic”: for the Romans, it accounted for up to 75% of the total; for the British Empire, it never fell below 55%. But in the long peace that began after the Second World War, governments have been able to stop splurging on weapons. In recent years, they have devoted an average of just 6.5% of spending to defence. That has enabled them to invest far more in things that make life better, such as healthcare, welfare and education.
This “new peace” was driven in part by the advent of nuclear weapons, and in part by the economic shift towards “knowledge”. (You can seize a vanquished rival’s silver mine; you can’t seize a Google engineer’s brain.) But it was also the result of a “cultural and institutional” change: the development, in effect, of a liberal global order based on the understanding that “all humans deserve the same basic liberties”, and that working together is better than trying to get ahead alone. The benefits are obvious – which decade in history was humankind “in better shape than in the 2010s”?
Alas, too many people took it for granted. Trump, Brexiteers and other populists set about tearing down the system, in the naive belief that “patriotic loyalties contradict global co-operation”. They assumed the world would just become “a network of walled-but-friendly fortresses”. But, as Putin has shown, fortresses can sometimes be unfriendly. If autocrats learn that “wars of conquest are again possible”, democracies will have to militarise themselves again. And given the weapons we have now, a new era of war “might be worse than anything we have seen before”.