What are the limits of political violence? Ebihara Toshio’s murder and the Umemoto-Kuroda controversy in 1970s Japan

On 3 August 1970, a student activist belonging to the Kakumaru-ha (Revolutionary Marxist Faction) was beaten to death by members of the rival Chūkaku-ha (Central Core Faction) at Hosei University, Tokyo. This incident sparked an intense war between Japanese New Left factions that stretched into the 1980s and resulted in dozens of deaths, making Japan a unique case among industrialized nations for its extremely high level of left-wing interfactional violence. Of particular importance in understanding the ideological factors surrounding such an escalation of violence was the debate triggered between Umemoto Katsumi, one of the intellectual founders of the Japanese New Left, and members of the Kakumaru-ha led by Kuroda Kan'ichi around the limits of political violence. This article explores the theoretical confrontation between these two opposing sides that was of such critical importance to the logic of war between Japanese New Left factions in the 1970s and 1980s.