If there is a thread that provides coherence to Donald Trump’s mad emperorship, it is the frenetic invention of new, evermore dramatic diversions: no week can be allowed to pass without new melodrama that erases the chaotic melodramas of weeks past. Nor can a week be allowed to pass without the seeds being sown for next week’s melodramas. This week it is Iran, and the computer-gaming unreality of a scorched-earth US-Israeli bombardment that has generated convulsions across economies in the...