¹ International Court of Justice, Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, July 8, 1996, General List, no. 95, para. 105.

² For example, see Singh, Nagendra & McWhinney, Edward, Nuclear Weapons and Contemporary International Law (1988)Google Scholar; see also Shaw, Malcolm N., Nuclear Weapons and International Law, in Nuclear Weapons and International Law at p. 1–21 (Pogany, Istovan ed., 1987 Google Scholar); International Court of Justice, supra note 1.

³ International Court of Justice, supra note 1, Dissenting Opinion of Judge Shahabuddeen at 1; id., Dissenting Opinion of Judge Koroma, at 3.

⁴ The international community is currently equipped with neither procedures that will deal promptly and effectively with violations of international law nor with organizations established for that purpose. As a result, the right of self-defense, based on the state’s own determination, is a kind of “self-help.” Superficially, the process of undertaking such an activity could be interpreted as an expression of sovereign right. However, the procedural aspects of self-defense are even more explicit in the UN Charter. This is because self-defense is stipulated in Chapter 7, Article 51, and is approved only in the event that the collective security system has not functioned, and that the Security Council places “self-defense” under its control.

⁵ Strictly speaking, in the event that the illegality of the threatened or actual use of ruclear weapons, from the view of substantive law, is not necessarily established, one cannot provide a definitive evaluation of the violations based on such an uncertain condition of “illegality.” Also, in reality, the three factors—”the legality of the threatened or actual use of nuclear weapons from the view of substantive law,” “procedural law that prevents violations” and “the existence of an agency that will implement procedures”—are mutually connected, and the existence of any of the three is dependent on the existence of the other two. This situation, one fears, will not change; therefore, the status quo will be maintained. However, if one factor should progress, then the other factors related to it might possibly also move forward. The present situation in international societies following the Cold War might well be considered to have concealed the possibility that the three factors above will progress, interacting mutually. So I venture to consider, in order, the relationship of these three factors, as it were, as so-called differential (as the meaning used in mathematics) or marginal (as per the meaning of “marginal utility” in neoclassical economic theory) concepts, each change contingent on the other two factors. Thus I began by discussing first the legality of the threatened or actual use of nuclear weapons in terms of substantive law.

⁶ For this kind of discussion, see A. Cassese, Violenza E Diritto Nell’era Nucleare, translated in Senso, Tero, Goumon to Kokushaiho 73 (Soga Hideo trans., 1992). In the United States, however, recently, in the American National Academy of Sciences Report the view has been expressed that the core function of nuclear weapons should be confined to deterring nuclear attack, or coercion by threat of a nuclear attack against the United States or its allies. “That is, the United States would no longer threaten to respond with nuclear weapons against conventional, chemical, or biological attacks.” See the Future of U.S. Nuclear Weapons Policy: Executive Summary of the National Academy of Sciences Report, 27 Arms Control Today, at 15-17, n. 3. (1997).

⁷ The theme in nuclear deterrence theory of how a cooperation system (role system) evolves from a mutual threat system is parallel to the problem in social theory of ho w role behavior evolves from interest-oriented behavior. Whether the interaction of the egoistic (self-interested) behavior of two or more parties automatically brings about cooperation or order is the central matter to the theory of social systems and decision theory. The conclusive explanation is that it does so under the following two conditions: (1) that communications and value systems intervene at the moment of systems transformation from relations based on the use of force to relations in which the use of force is deterred (for details, see HlRose Kazuko, Funso to Ho: Sisutemu Bunseki Niyoru Kokusaihoshakaigaku No Kokoromi [Disputes and law: A treatise on the sociology of international law according to systems analysis] 124-34 [1970]; Kawashima Takeyoshi, Nihonjinno Ho-Ishiki [The consciousness of law of the Japanese people] 22-25 [1967]); (2) that certain attributes of the actor itself toward the other actor in context of interaction are premised. Robert Axelrod finds these attributes to be niceness, provocability, forgiveness and clarity. These attributes represent the minimum rationality expected of an actor engaged in deterrence. In other words, they are associated with the capacity of an actor to decide its action, corresponding to the other’s capacity and attitudes. See Robert Axelrod, the Evolution of Cooperation, 20-35, 40-54 (1984).

⁸ These security assurances were given via the separate unilateral statements made by the nuclear states on April 5 and 6, 1995, in the context of the extension of the Npt. These assurances were fully recognized by the Security Council through Resolution 984, unanimously adopted on April 11, 1995. International Court of Justice, supra note 1, paras. 45, 59. The same kinds of statements were also given in Security Council Resolution 255, in 1968.

⁹ However, the nuclear-weapon states, apart from China, reserved the right to use nuclear weapons in the case where they or one of their allies was attacked by another of the nuclear-weapon states and/or their allies. Here, special attention should be paid to the possibility that this exception could be interpreted as referring to an illegal act on the part of the other party, without which the nuclear weapons would never be used. In 1978, China declared categorically that it would never use nuclear weapons against a non-nuclear-weapon state or within a nuclear-free zone, and that it would never conduct a first attack with nuclear weapons regardless of time or circumstance. Singh & McWhinney, supra note 3, at 318-19. See also Casseze, supra note 6, at 73-74.