As World War II approached, Seversky became engrossed in formulating his theories of air warfare. Shortly after the Attack on Pearl Harbor, he wrote "Victory Through Air Power", published in April 1942, advocating the strategic use of air bombardment. The best-selling book (No. 1 on the New York Times bestseller list, appearing first in mid-August 1942 and remaining in first place for four weeks) with five million copies sold. The book's popularity and hard-hitting message led to Walt Disney adapting the book into an animated motion picture (1943) of the same name where Seversky (who also served as the film's technical consultant) provided live-action commentary. The Disney animated film received a lukewarm reception at the box office and from critics who felt it was an unusual departure from the standard Disney studio fare, sending out a powerful propaganda message based on an abstract political argument. The influence of both the book and film in wartime, however, was significant, stimulating popular awareness and driving the national debate on strategic air power.