Inflation’s return marks a tipping point. Demand has hit the brick wall of supply. Our economies are now producing all that they can. Moreover, this inflation is clearly rooted in excessively expansive fiscal policies. While supply shocks can raise the price of one thing relative to others, they do not raise all prices and wages together.

A lot of wishful thinking will have to be abandoned, starting with the idea that governments can borrow or print as much money as they need to spray at every problem. Government spending must now come from current tax revenues or from credible future tax revenues...