Psalm 137 famously depicts Israelite exiles sitting “by the rivers of Babylon” mourning their lost homeland. Required by their captors to “sing . . . one of the songs of Zion,” they begin with the oft-quoted “If I forget thee, O Jerusalem, let my right hand forget her cunning.” But the less well-known final verses of the psalm strike a very different note:

Twenty years after Britain outlawed Hamas’s military wing, the home secretary, Priti Patel, has decided to proscribe the entire organization. Stephen Daisley applauds this decision, but observes that London does not yet seem to recognize the dangers of what Hamas represents: