Growing up in 1970s Belfast, my colleague recalls the bleakest days of the Troubles. There had seemed a terrible inexorability in the unfolding of the history through which he lived, as if there were no possibility of anyone ever calling a halt to the violence.

Drinking tea, we recalled accounts of a moment when all that was to follow might have been averted. Bernadette Devlin, a young and fiery republican socialist, had sat and drunk tea with Ian Paisley, the rising firebrand of loyalism. The stories of tea in china …