During World War II, the entertainment industry changed to help the war effort. Often the industry became more closely controlled by national governments, who believed that a supportive home front was crucial to victory. Through regulation and censorship, governments sought to keep spirits high and to depict the war in a positive light. They also found new ways to use entertainment media to keep citizens informed.
Government censorship of mass media was enforced because of fears of threats to national harmony and security. The most popular forms of entertainment were radio, film, and music. Together these aimed to keep citizens entertained, informed about the war effort, and motivated. Broadcast radio was an especially powerful communication tool.