The last time the world faced a concerted attack on the international order from multiple enemies was in the 1930s with the expansionist policies of the Italian Fascists led by Benito Mussolini, Nazi Germany under Adolf Hitler, and Imperial Japan led by Hideki Tojo. On the European front, Mussolini made the first violent move when his forces invaded Ethiopia in 1935 and then proclaimed the formation of a Rome-Berlin Axis. Hitler, impressed at first, eventually found Italy’s aggressive performance wanting, especially its failed military effort in Greece. Hitler soon asserted leadership of the Nazi-Fascist alliance and demonstrated in his own...