This paper aims to indicate that discussions on policy effects regarding dispatching Japan Self Defense Forces (SDF) abroad for collective security seem to have hardly taken place in the National Diet over the past quarter of a century. It also intends to promote the revitalization of policy debate through showing disputing points that should be concretely discussed in the Diet. In general, policy debate should include discussion of both whether implementation of the policy is legally permitted (legality debate) , and whether implementation leads to the achievement of the expected goals (policy effect debate) . This is because there are policies that are legal but ineffective and those that are effective but illegal. However, almost all discussions of joining in collective security in the Diet have been centered on a legality debate.

On collective security, experts have mainly discussed (i) whether the deployment of forces influences peacekeeping and peacebuilding in intervened states, (ii) whether the deployment of forces has a harmful effect on intervened states, and (iii) whether the definition of policy effect is appropriate in the first place.

Regarding these disputing points, the debates are still on-going. On the other hand, in the Diet, it appears that policy effects have been addressed as if they were simply obvious. If one is to support the active deployment of the SDF to missions abroad, an assessment of policy effects should be presented as its basis. However, their discussions have focused on the interpretation of Article 9. It has been a “policy debate without policy effect debate.”

Considering this, this paper recommends that the Diet start an assessment of the policy effects of SDF deployment in past cases, based on the three points of dispute mentioned above. After the assessment of past cases, it will be possible for the Diet to carry out a “policy debate with both legality debate and policy effect debate.”

This article aims at investigating the significance of the draft provisions on piracy, commonly known as “Matsuda Draft,” submitted by Michikazu Matsuda, a Japanese lawyer-diplomat, to the League of Nations Committee of Experts in 1927, by examining the historic and legal background of the draft and Matsuda’s views on international law.

The Committee of Experts was established by the League in 1924 and consisted of international lawyers from various countries to select topics of international law to be codified. Matsuda Draft, together with the so-called Harvard Draft, is widely known among current scholars as an important precedent of the formulation of the concept of piracy in international law. However, it is still unclear how the draft was drawn up and what kind of historical significance it has for the relationship between Japan and international law in the interwar period. This study compares the original text, which was initially submitted by Matsuda to the Committee, with the final draft, and then clarifies the background to the drafting of this document and its historical significance.

Matsuda Draft was the first official attempt to formulate a definition of piracy. What is more important from the perspective of the history of Japan’s relationship with international law is that a Japanese international lawyer prepared a report on piracy, consolidated the various opinions expressed on it by the experts in the Committee, and reflected them into a draft treaty. This fact provides a basis to reconsider the conventional view that prewar Japan was reluctant or negative about the development of international law.