With the United States’ disastrous exit from Afghanistan, the parallels between the 2020s and the 1970s just keep growing. Has a sustained period of high inflation just become much more likely? Until recently, I would have said the odds were clearly against it. Now, I am not so sure, especially looking ahead a few years.

Many economists seem to view inflation as a purely technocratic problem, and most central bankers would like to believe that. In fact, the roots of sustained inflation mainly stem from political economy problems, and here the long list of similarities between the 1970s and today is un...