This article explores the role of metaphor in structuring political reality for manipulative purposes. The research is mainly limited to an analysis of nuclear allergy as political metaphor. This metaphor was used most predominantly in the late 1960s to brand opponents of Japan's nuclearization as 'allergic'. By locating antinuclear sentiments in the medical context of disease, those trying to nuclearize Japan were able to invoke the entailment of the need for a 'cure'. A gradual increase in the number of nuclear-powered (and undoubtedly nuclear-weapon loaded) U. S. ships and submarines making port calls to Japan, criticism of the antinuclear sentiments from the viewpoint of 'international common sense', and the initiation of a propaganda campaign, were used to try to 'cure' the Japanese people's antinuclear 'allergy'. The metaphor functions by transferring the image of 'harmlessness' associated with an allergen to nuclear weapons, and by transferring the image of 'abnormal' associated with a reaction to an allergen to those Japanese opposed to nuclear weapons. Four conclusions are drawn: 1. the metaphor played an important role in structuring political reality; 2. labelling opponents as 'allergic' undermined the democratic discourse; 3. analyzing the inner workings of a metaphor can expose its manipulative power; 4. peace researchers, educators and activists need to exercise care in the use of metaphors and help to promulgate countermetaphors useful for denuclearization.