Japan Institute for National Fundamentals

　　　　　　　The right of collective self-defense is a concept under international law. The government has maintained its view that "Japan has the right of collective self-defense while being banned by its Constitution from exercising the right." While discussing problems involving domestic law (the Constitution) and international law (the United Nations Charter), the government’s view adopts the logic of domestic law alone. As far as the Constitution's Article 98-2 calls for its compliance with international law, however, the government may have to give considerations to the view's consistency with international law.
　　　　　The criterion for interpreting treaties is quite different from that for interpreting domestic laws. When interpreting a domestic law, we must consider various relevant factors besides its legislative objectives. As for international law, however, the collective intention of original parties to a treaty, or its legislative objectives, is a decisive criterion under the principle of absolute sovereignty.

Intention of original parties to U.N. Charter
　　　　　　　Customary international law allows a sovereign state to exercise its right of self-defense to counter imminent and unlawful attacks on itself or any other countries. This represents a concept parallel to the legitimate self-defense under domestic law. For example, Article 36 of Japan's Penal Code says, "An act unavoidably performed to protect the rights of oneself or any other person against imminent and unlawful infringement is not punishable." Both customary international law and domestic law refrain from separating attacks on one’s own country (oneself) from those on any other countries (any other persons) regarding the right of self-defense.
　　　　　　　The right of collective self-defense is a new concept introduced by the U.N. Charter. Its interpretation should be based on the history of deliberations at charter-drafting meetings.
　　　　　　　The Draft U.N. Charter had included a provision that would give the Security Council dominated by the Big Five absolute authorities on peace and security problems, but exceptionally to allow each U.N. member on a priority basis to exercise the right of self-defense. The provision came under opposition from a wide range of countries led by American states.
　　　　　　　Just before the draft was unveiled, American states had adopted the Act of Chapultepec, intending to establish the Organization of American States and to conclude the Inter-American Treaty of Reciprocal Assistance. They were then concerned that the Security Council could interpret the right of self-defense discretionarily narrowly and refuse to admit the presence of regional arrangements or agencies. They thus attempted to limit the Security Council's absolute authorities.
　　　　　　　The dispute was solved as the Big Five eventually agreed to give regional arrangements or agencies priority to solving their regional conflicts. In this way, the concept of the right of collective self-defense was introduced to totally secure the right to self-defense under customary international law. None of U.N. Charter drafters attempted to separate collective self-defense from individual self-defense or emphasize the right of collective self-defense.

Impediment to future participation in regional security arrangements
　　　　　　　The right of collective self-defense is a legal basis for countries to conclude security treaties. When the treaties take effect, parties to them will be obligated in principle to exercise the right.
　　　　　　　If Japan denies its exercise of the right to collective self-defense, therefore, it may face unforeseen obstacles. In case of the Japan-U.S. security treaty, Japan is obligated to exercise the right of collective self-defense only in the territories under the administration of Japan. But Japan's right of collective self-defense outside these territories is still effective. I doubt if the Japanese government got U.S. approval on its view that Japan cannot exercise the right of collective self-defense. If Japan sticks to the government view, it may amplify U.S. distrust. Furthermore, the government's continued denial of the exercise of the right of collective self-defense may deter Japan not only from proposing new collective security arrangements in developing future defense strategies but also from participating in such new arrangements.

Rikiwo Shikama is a former Japanese ambassador to Chile and Guest Researcher of JINF.