When World War I broke out in August 1914, economists on both sides forecast that hostilities could not last more than about six months. Wars had grown so expensive that governments quickly would run out of money. It seemed that if Germany could not defeat France by springtime, the Allied and Central Powers would run out of savings and reach what today is called a fiscal cliff and be forced to negotiate a peace agreement.

But the Great War dragged on for four destructive years. European governments did what the United States had done after the Civil War broke out in 1861 when the Treasury printed greenbacks. They paid for more fighting simply by printing their own money. Their economies did not buckle and there was no major inflation. That would happen only after the war ended, as a result of Germany trying to pay reparations in foreign currency. This is what caused its exchange rate to plunge, raising import prices and hence domestic prices. The culprit was not government spending on the war itself (much less on social programs).

But history is written by the victors, and the past generation has seen the banks and financial sector emerge victorious. Holding the […]