Japan is a historical example of a country that has progressed from a closed feudal society to an industrialized nation without being colonized. Most accounts have historically misrepresented the nature of Japan’s policies with respect to westernization and have failed to recognize how it implemented mechanisms of adaptation. This chapter examines the Japanese experience of managing external threats from the Sengoku period to the contemporary period. The historical development of Japan’s governance and diplomatic frameworks are examined to trace the transition from the sakoku to the Meiji restoration and post WWII economic reform. The findings of this chapter show that Japan’s sovereignty was preserved, not through total isolation, but through selective closure and a discriminating adoption of foreign technology, while preserving core aspects of Japan’s cultural identity. This study identifies how Japan was able to utilize a strategic selectivity policy to transform the pressure of external forces into drivers of internal modernization. These results provide empirical evidence to challenge state centric realist theories of international relations and identify a model of managed autonomy applicable to middle powers currently experiencing technological dependency and great power rivalry.