As the might and capabilities of American airpower have grown during the last 60 years, so has the controversy about its use in the intentional and indiscriminate wartime bombardment of civilians. In Bombs, Cities and Civilians, Conrad Crane maintains that, for the most part, American airmen in World War II remained committed to precision bombing doctrine. Instead of attacking densely populated urban areas simply to erode civilian morale, Army Air Forces adhered to a policy that emphasised targeting key industrial and military sites. He demonstates that while the British, Germans and Japanese routinely conducted indiscriminate aerial bombardment of enemy cities, American airmen consistently stayed with daylight raids against carefully selected targets, especially in Europe. Daytime precision missions were usually far more dangerous than night area attacks, but such Army Air Forces tactics increased bombing efficiency and also reduced the risk of civilian casualties.