Richard Sennett lives near Hatton Garden in central London. His patch sounds just the type of “iconic mixed neighbourhood” to suit a prolific and eclectic writer who explores how dissimilar people can find better ways to live and work together. Usually, he reports, the local mash-up of Hasidic Jewish jewellery workers and traders, “native-born English working-class” and younger incomers “from across the Islamic world” does “chug along” in harmony. Then came the safe-deposit burglary of April 2015.

On the street, this already mythical heist stoked rumours so that “ethnic tensions rose to the surface”. “Anti-Semitic remarks” in the halal cafe began to bug Sennett. Then, spontaneously, the community noticed the danger and began to row back. When not talking in Yiddish or Hebrew on their mobiles, the diamond craftsmen would coo over the babies of Muslim mothers from a nearby estate: “So big for seven months!” An imam advised youngsters not to fly Palestinian flags. A recourse to “light, superficial civilities” helped avert a damaging rift.