China, Japan and South Korea are three big economies in Northeast Asia that are innegotiations for a trilateral Free Trade Agreement (FTA). A concluded FTA among them willcreate world’s third largest regional market that consists of of 1.52 billion people and thataccounts for 20% of world’s GDP. However the economic cooperation between the threecountries has constantly been interrupted by political issues that root back in the history of thethree countries. In the history the three countries have developed enemy images of oneanother, which have restrained their interaction over the years and influenced their currentrelationship. This thesis uses the enmification theory to explain how these enemy images andenmity feelings have emerged in the history and what impacts they have on political issuesand the economic cooperation between the three. Examples on political issues that are broughtup in this thesis are the recent intensified territorial disputes over Diaoyu/Senkaku islands andDokdo/Takeshima islands.

Since the Open-Door Policy has been carried out in 1979, China has gained dramatic improvements in many fields, such as economies and military. At the same time, the considerable changes also bring China many crises from the complicated international envirorunent. This thesis will illustrate these questions through nationalism and realism theoretical framework by using case study with a qualitative approach as the method. With the Five Peaceful Principles of Co-existence based foreign policy, this thesis will experience "Century of Humiliation" of China again and redefine the rising power of China through a case study about Diaoyu/Senkaku Islands dispute between China and Japan. Although it is a little hard to analyze this case under a complicated international environment, plenty of document information will support to get a result of how China's foreign policy and national security are interlinked? Finally, "national insecurities" and "humiliating history" are drawn as the key factors that affect China's foreign policy making, and the interconnections of China's peaceful diplomacy and national security. "National insecurities" and "humiliating history" drive China to make the foreign policy of peaceful development, otherwise, to ensure national security, China need to strengthen the comprehensive national power.