The “Citizens’ League for Peace in Vietnam,” also known as “Beheiren(short for Betonamu ni Heiwa o! Shimin Rengo),” was a Japanese civil movement organization that opposed the Vietnam War. Its central idea was the “victim = aggressor” mechanism, created by Makoto Oda, which suggests that victims and aggressors are not necessarily dichotomous, and that a victim can also become an aggressor. This theory was based on the perception that Japan, which supported the Vietnam War behind the scenes through the Japan-US Security Treaty, was a victim of the United States but an aggressor toward Vietnam. Through this concept, Beheiren reminded postwar Japanese society—immersed in its victim consciousness—of its responsibility as an aggressor, while also attempting to connect oppressed groups such as the Okinawan people, Asian minorities such as Koreans and Chinese in Japan, and even African Americans, who faced discrimination not only in the United States but also on the battlefields of Vietnam and at US military bases in Okinawa. Beheiren called for Asian-Third World solidarity against American racism and imperialism. However, Beheiren’s vision of solidarity, which sought to bridge the gap between oppressed Asian peoples and Japan as a historical oppressor and aggressor, had limitations due to the positional differences that persist in new forms between Japan and other Asian countries—living in the era of postwar peace and the era of Cold War suffering. This study explores whether the victims and aggressors of history can find unity through Beheiren’s efforts and challenges the current generation to consider how we might overcome the seemingly insurmountable gap between victims and aggressors.