A core claim of liberal international relations theory is that economic exchange engenders peaceful interstate relations through the creation of common interests. International businessmen desire that their home governments avoid national policy lines that offend the foreign countries on which their businesses depend. As a result, if such offensive behaviors occur, businessmen protest to their politicians, who then act to moderate their governments' political-security policy. This thesis examines the liberal claim using the case of Japan's relationship with China since the Koizumi administration began in April 2001. During this ten-year period, Japan's economic dependence on China grew rapidly, with China overtaking the United States as Japan's number-one trading partner in 2004, and becoming the top destination for Japan's foreign direct investment in 2010. Given the weakness of Japan's domestic economy, this booming interaction with China was seen as helping Japan to rise out of its long recession and recover vitality. During this decade, China evolved into an indispensible economic partner for Japanese businesses, as a source for manufacturing capability, inexpensive labor, natural resources, and, most promisingly, consumption of Japanese products. Yet, contrary to the liberal claim, Japan's economic dependence on China did not moderate Tokyo's political-security policy toward Beijing. At the same time that Japanese trade and investment flows to China intensified, Tokyo's political and security relations with Beijing became complicated by nationalist conflicts and China's growing military power. Due to different views of history, Japanese people grew frustrated and lost affinity toward Chinese people. In response to concern about the assertive activity of the PLA Navy in the East China Sea,the Japanese government exercised several countermeasures, including strengthening the capability of the SDF and enhancing cooperation inside the Japan-US alliance. This thesis reviews the economic, political, and security aspects of Japan's interaction with China since the Koizumi administration, which show contradictory developments in Japan's economic policy and political-security policy toward China during these ten years. It then looks deeper at the political significance of Japan's economic dependence on China, through inspecting three hypothetical causal linkages across which economic dependence can moderate national policy. With a few notable exceptions, the scarcity of evidence to support these linkages underlines the absence of economic dependence's pacifying effect on Japanese political-security policy toward China. Based on this finding, the thesis concludes that Japan's economic reliance on China did not bring Tokyo closer to Beijing on political and security issues between 2001 and 2011, and did not significantly influence the strategic structure of the China-Japan-US triangle.