London Bridge is finally falling down. No fresh sacrifices can save Britain.

TEHRAN — The children’s nursery rhyme has been sung for centuries, its jaunty rhythm masking a foundational horror. “London Bridge is falling down, falling down, falling down...” What the melody glosses over is the grim medieval folklore of immurement, the belief that a grand structure could only be preserved from collapse if a living soul, often a child, was entombed alive within its masonry.