The British left intermittently erupts like a pustule upon the buttock of a rather good country. Seventy years ago it opposed mobilisation against Adolf Hitler and worshipped the other genocide, Josef Stalin. It has marched for Mao, Ho Chi Minh, Khrushchev, Brezhnev and Andropov. It has slobbered over Ceausescu and Mugabe. It has demonstrated against everything and everyone American for a century.