The flag movement took off in the wake of the Epping protests. An online group of “proud English men” called for the waving of the St George’s cross and Union Jack, and flags started going up everywhere from Bromsgrove and Worcester to Bradford and Norwich. Some of those attached to public buildings were taken down, in part because of the worry that it was all the work of the far right — and it’s doubtless true that extremist activists are linked to the movement. But the broader phenomenon is, I think, quite different and more complex. Perhaps the key thing...