From a foreigner's point of view, I think this movie was made to satirize just how paranoid and scared of an invasion, the americans were during world war II, to the point that they would start riots on their own and battles even when the japanese had not yet arrived. Sure, it was over the top and not all the jokes were funny. Agree?
I wrote that because apparently a lot of people on this board seem to have missed the whole point of the film, and are bashing it nonstop. My point was to open people's eyes
Whatever the intention of the original scriptwriters, etc, the movie comes over depicting in a darkly humorous way a sequence of historical events. It's true that there was some fear of Japanese invasion on the west coast in the time immediately following the Pearl Harbor attack. This fear was not lessened by events depicted in the movie, such as: Japanese submarine attack (actually happened near Santa Barbara Feb. 1942) and the imaginary air raid over Los Angeles in Apr. 1942 (the work of trigger-happy American anti-aircraft gunners). There are other references in the film to actual events of the time, such as US Army maneuvers in the Mohave Desert, the Zoot Suit riots, etc.
I've wondered if the location of a major part of the film industry (at the time) had something to do with the advancement of this film. Meaning, perhaps people in the business with some background in the southern California area might have found this whole subject more appealing than someone from Salina, Kansas.
I still think it'd be interesting if in 30 years or so, someone does the same about the events of 9/11. I once thought up a grade gag of a guy who was so crazy that the Taliban were gonna take over his farm, that he carried his shotgun with him everywhere. One evening, he almost kills his wife because she had her hair wrapped up in a towel. It sounds stupid, but I'd bet someone would be paranoid enough to do such a thing.
The country then went into full-on panic mode, but I wonder if anyone could come up with the dark-comedic humor that would be akin to 'Dr Strangelove' and '1941.'