After the Second World War, the Australian military prosecuted almost a thousand alleged Japanese war criminals. These prosecutions were not only an attempt to punish Japan for its wartime militarism, but also a move to exert influence over the future course of Japanese society, politics, and foreign policy, as well as to cement Australia’s position in the Pacific as a regional power. During the Allied occupation of Japan (1945-52), Australia energetically pursued Japanese war criminals, and took a tough stance on Japan in general. The U.S. authorities, who dominated the Occupation, initially took the same line. As the Cold War in Asia intensified in the late 1940s and early 1950s, however, the U.S. government ceased to consider Japan a threat to Pacific security, and instead began to cultivate Japan as a potential democratic ally against communism. By the end of the Occupation, U.S. officials were firmly committed to pursuing good relations with the Japanese government. Gradually, in the 1950s, the Australian government came to share the U.S. view of Japan. As Japan shifted in official thinking from being a former foe, to a potential economic and political partner, concerns about the guilt of individual Japanese soldiers made way for pragmatism and political gain. The war criminals became entangled with Australian moves to establish good relations with Japan, and to draw the U.S. into a close alliance. Variations to their sentences - through repatriation to Japan, and later through parole or other forms of early release - became diplomatic bargaining chips. By the end of 1957, all of the surviving war criminals prosecuted by Australia had been released.
Howard Brick & Christopher Phelps. Radicals in America. The U.S. Left since the Second World War. New York: Cambridge University Press, 2015