According to the article "On the Battlefront" by Clyde Jeavons in the film history tome 'The Movie', " . . . out of approximately 1700 features produced between 1942 and 1945 over 500 [or about 30%] were war films of one kind or another."
This documentary that the Japanese in World War II movies were frequently played by Koreans, Hawaiians or Phillipinos. Going Hollywood: The War Years (1988) states that many Japanese characters in films of the World War II period were actually played by Chinese actors. This was because 112,000 Japanese-Americans, who had lived in the USA for years, were transferred to relocation centers and "stripped of their property" during WW 2.
Before World War II was over, according to this doc, Hollywood movie stars had exceeded every war bonds quota given to them by the US Government Treasury, exemplifying the power of their appeal. An original target of $ US 500 million was exceeded, amounting to $ US 16,080 million. During the Second World War, Hollywood movie stars sold billions of dollars worth of war bonds.
Originally, Hollywood movies were impartial and neutral to the Second World War during America's isolationist period, before they entered World War II. But according to this documentary, the films eventually started to take sides and added propaganda messages to their movies.
According to this documentary, World War II was a time of a great need for entertainment and the movies were a great way for the citizens on the home front to get entertainment. Large movie attendance during the Second World War can be attributed to such factors as gas rationing, limited travel, overcrowding in cities, patriotism, support of the war effort, little or nil unemployment, blackouts, morale building and surprisingly, high wages. Entertainment also came from radio and the stage, the latter of which Hollywood movie stars entertained on, also for the war effort.