Arasaki Moriteru (1936-2018) left a singular body of work on postwar Japan. For over half a century, he had been a leading critic of Japan's involvement in the San Francisco System, a political architecture centred around the US and its regional allies in Asia and the Pacific. In newspaper columns, essays, and books, the Okinawan historian wrote numerous pieces on the subject, particularly on the enduring political and social struggles on the US military base problems in his home, Okinawa. Since his first published book on the early development of Okinawa's anti-colonial movements against the US military government in 1965, Arasaki had dedicated his whole professional life over four decades to writing about Okinawa's grassroots politics in both historical and contemporary terms, which led to the establishment of 'Okinawan contemporary history' as a genre of historical writing. Despite his intellectual legacy, which is certainly unique, his thoughts behind the historical writing have rarely been examined. In this paper, I intend to highlight some key aspects of his historical thought and show its relevance beyond local and national confinements by situating it in broader theoretical discussions on history and politics, especially in light of what Ariella Azoulay's concept of potential history. I argue that it enables us to reframe the history of Okinawan anti-base politics as a record of not just past social activism but of the critical struggles towards multiple forms of de-imperial futures.