Throughout this century scholars have been intrigued by the history of ‘strategic bombing’ – aerial bombing done well beyond the battlefront for the purpose of destroying or undermining the enemy’s ability to fight, and will to fight. A large body of writing has been devoted to the subject, especially pertaining to its history in Britain and the United States. Indeed since 1980 the pace of inquiry has increased, producing at least 20 noteworthy studies.1 For the most part these have focused on particular issues or time periods, and have not been explicitly comparative in nature. The purpose of this essay is to offer a sustained inquiry into the development of thinking about strategic bombing in both Great Britain and the United States, from the beginning of World War I through the end of World War II. Such an approach will illuminate the way in which each nation interpreted the ‘lessons’ of World War I and carried them into the future; it will highlight both similiarities and differences in thinking, and the reasons for them; and finally it will facilitate a better understanding of the operation of the Combined Bomber Offensive (CBO) of World War II.