This article re-examines the historical process of framing Article 9 of the Constitution of Japan, which is called Renunciation of War Clause, and focuses on its function as reassurance by the loser. Dealing with the function, this research explains the reason why postwar Japan-U. S. relationship could dramatically progress conflict resolution from the total war to the restoration of peace from both theoretical and historical standpoints.

To answer the question mentioned above, this article argues that, in terms of a theory of reassurance by the loser, Postwar Japan intended to treat the victor’s anxiety on its challenge by relying on the normative self-restraint of Article 9 of the Constitution. The argument regards the provision of the Article as a signal justified by an appropriate norm. While the U. S. was concerned about Japan’s challenge and intended to make it impossible by prohibiting armament, Japan dealt with the fear of the U. S. by reassuring its own intention. Japan sent a normative signal of reassurance, which bound itself by denying war and armament. Therefore, it is appropriate to understand that, in essence, Article 9 of the Constitution had practical meaning as a signal of reassurance in order to let the U.S. and other countries know Japan’s peaceful intention, rather than an abstract norm derived from the idea of pacifism, which came from regret for the war.

Tracing the historical process of framing Article 9 of the constitution reveals that it worked as the loser’s reassurance. The process was the opposite direction of the order of the completed text. The U. S. home government decided to disarm Japan at first, and the local commander MacArthur followed the policy. On the other hand, as Japanese leader, Prime Minister Shidehara proposed renunciation of war to MacArthur. However, it was just an ideal promise regarding peaceful intention, and lacked reassurance in terms of the capability. The Japanese government hoped to maintain the provision of armament in the constitution. It was unacceptable for the U.S., so it prepared a draft of the constitution which included renunciation of war proposed by Shidehara as well as the prohibition of arms. The U.S. presented the draft to Japan in order to confirm its peaceful intention. The draft imposed the cost of the prohibition of arms, while it mitigated the impression of burden by referring to the normative legitimacy of renunciation of war. The draft as the U.S. screening set up a hurdle that Japan should clear. Japan reassured the U.S. and other members of the international society by sending a signal which became costly due to the democratic institutional constraint of diet deliberations. It made Renunciation of War Clause a national pledge.