「休戦ライン」としての核不拡散体制

―衝突する規範の妥協と二重基準論争―

抄録

What are we to make of recurrent acrimonious debates over “double standards”—the injustice of treating like cases differently—in international politics (e.g. the nuclear nonproliferation regime)? I argue that this is best understood as a product of constant clashes among mutually-opposed universalist norms in international society and fragile compromises or “cease-fire lines” that have developed out of them. Those unstable “cease-fire lines” arouse fierce debate over “double standards”: rejectionists would reject outright the need to compromise; revisionists would seek to re-demarcate the line while quietly accepting the need for a compromise; conservatives would be keen on preserving the status quo. A “ceasefire line” can be stabilized either by gradual accumulation of legitimacy via conventionalization or by promotion of the perception that cases that are treated differently are actually different in nature.

In the case of the nuclear nonproliferation regime, the “cease-fire line” centered around the NPT had emerged out of clashes between two diametrically-opposed universalist norms about the legitimacy of nuclear weapons: self-defense and humanitarian concerns. This compromise was made possible by two “segregations” of the norms, one temporal and the other spatial. The temporal segregation allows self-defense to prevail for some time and humanitarian concerns thereafter concerning five NWSs. The spatial segregation allows self-defense to prevail in NWSs and humanitarian concerns in NNWSs. Since the spatial segregation amounts to illegitimate institutionalization of NWSs’ fait accompli, efforts were made to legitimize it by the temporal segregation, the right to the peaceful use of nuclear energy, and a subtle distinction between “responsible NWSs” and “irresponsible NNWSs” implied by the “proliferation” metaphor. Citing the “double standard” of the treaty, however, even some of those that are qualified as NWSs like France and China refused to sign the NPT until the end of the Cold War.

The fragility of the two “segregations” allows the dissatisfied to challenge the “cease-fire line” and thereby arouses debate on the “double standards” on several fronts. Firstly, ambiguity of the line between peaceful and military use of nuclear energy allows a NNWS to disguise its military program as peaceful, thereby spatially expanding the sphere where self-defense prevails while accusing NWSs of doing the same thing, albeit of the temporal kind. Secondly, lack of legitimacy in the outright approval of NWSs’ fait accompli makes it vulnerable from further attempts to spatially expand the sphere where self-defense prevails since a “latecomer” can also create a new fait accompli by acquiring nuclear capability. Thirdly, ambiguity of the time frame for disarmament allows NWSs to keep their nuclear weapons almost indefinitely, i.e. to temporally expand the sphere where self-defense prevails while accusing NNWSs of doing the same thing, albeit of the spatial kind.