International relations theory and Japanese pacifism: Why didn’t Tokyo go ballistic over North Korean nukes?

Seen from the perspectives of the various Western theories of international relations, Japan’s peculiar armed pacifism can appear very different. Prominent neorealists have predicted that Japan will inevitably develop nuclear weapons; prominent liberals have cited Japan as the model pacifist nation of the future. Over the last five years, it became clear to Japan that North Korea either possessed, or was on the brink of acquiring, nuclear weapons. How would the Japanese government respond to such a critical threat to its security? The case of North Korean nukes suggests that policymakers should be wary of the grim expectations of Western neorealists, at least in regard to Japan.