"Prelude To War" is one of seven films in Frank Capra's "Why We Fight" 1940's series.
It describes World War II as a battle between the "slave world" of fascism and the "free world" of American liberty. In the "slave world," the entire populations of Germany, Italy and Japan have been hoodwinked by madmen, opportunists who capitalized on their people's desperation and weakness to rise to power.
These demagogues promised revenge for past losses, and in the process convinced their people to give up their rights and accept dictatorship. In the "free world," the principles of equality, freedom, and liberty characterize the greatest leaders, embodied in the works and words of Washington, Jefferson, and Lincoln. This freedom is a threat to the fascist dictators of the Axis powers, who claim that democracy is weak and must be eradicated.
The film claims that the ultimate goal of the Axis powers is to enslave the nations of the "free world," a desire made manifest in the Japanese invasion of Manchuria and Mussolini's destruction of Ethiopia.