Between 1941 and 1945, American and British air forces dropped 1.5 million tons of bombs on German and Japanese cities, causing destruction that is difficult to imagine today. The memory of this event differs in the historiography and public debate on the one hand and in the field of “strategic studies” on the other hand. In the former, the gaze has become mainly critical, including in the United States and the United Kingdom, as regards both the morality and the effectiveness of the bombings. In the field of “strategic studies,” on the other hand, an articulated discourse states that these bombings may have constituted a lesser evil and that some of them, including those which targeted civilians, have been militarily effective. This text questions the reasons for the fragmentation of civilian and military memories of the Allied bombings of World War II. The argument is that an expertise played a key role in the social construction of the strategic studies' assessment of the Allied air war: the United States Strategic Bombing Survey.