The world is changing and becoming even more dangerous — in a way we’ve seen before.
In the decade before World War I, the near-hundred-year European peace that had followed the fall of Napoleon was taken for granted. Yet it abruptly imploded in 1914. Prior little wars in the Balkans had seemed to predict a much larger one on the horizon — and were ignored.
The exhausted Austro-Hungarian and Ottoman empires were spent forces unable to control nationalist movements in their provinces. The British Empire was fading. Imperial Germany was rising. Czarist Russia was beset with revolutionary rebellion. As power shifted, decline for some nations seemed like opportunity for others.