‘Are we beasts?’ asked Winston Churchill one night in 1943 after watching a film of the bomb damage done to Germany. The question was probably rhetorical: Churchill had authorised the bombing campaign from its puny beginnings in 1940 to the massive Combined Offensive launched with the American air forces in the last two years of war. His language was always intemperate and flowery – ‘extermination’, ‘annihilation’ and so on. Did he mean it? Did the British military machine set out deliberately in the Second World War on a path to the genocide of the German people?