The Second World War had a central role in the history of Britain's Labour Party. The experience culminated in the party's success in the 1945 general election, a victory that was held to have been the result of its concentration on domestic policy planning and in promising the public a welfarist post-war settlement. It has almost been assumed that Labour was not involved in the strategic or operational conduct of the war, including what was the first, became the longest-standing, and has remained the most controversial, aspect of Britain's waging of war: strategic, area, or ‘obliteration’ bombing. The disposition of what some maintained was - or should be - an internationalist party of working people towards the mass killing of civilians has not formally been considered before: whether the party approved of the policy or how far it merely had other (it may have felt) more-pressing priorities. Such an examination illustrates ‘labourism’ in the war and in its ambivalence towards Europe and Europeans also, perhaps, afterwards.