Photo by Haywood Magee/Picture Post/Hulton Archive/Getty Images Across the West, the left seems incapable of defining a politics for our age of insecurity. It oscillates between electoral caution to reassure middle-class swing voters, and impossible utopian visions to satisfy militant members. But neither strategy will deliver majority support nor engender radical reform. At a time when politics is small and inversely related to the scale of the task, the left should remember its radically transformative traditions, such as the postwar settlement ushered in by the Attlee government. Yet both in office and in opposition, the left is rowing back its...