I. Introduction East China Sea consists of eight uninhabited islands and rocks. The islands’ total size is about seven square kilometers, lies in north-east of Taiwan, east of the Chinese mainland and south-west of Japan’s southern part, Okinawa. These islands contain a lot of potential oil, natural gas reserves and best to build up the military exercise. It is also close to important shipping route and rich fishing ground which is best for the country to develop the economic (BBC, 2014). After the end of World War II in 1895, Japan were formally claimed and controlled over the Senkaku/Daioyu islands and privately owned by Japanese citizens for the past 120 years. However, in 1970s China began to reassert claims over the islands by citing rights to the area. Since then, both sides have increased efforts to assert sovereignty over the disputed territory. Recently in 2012, the tension between China and Japan resurfaced again over the disputed island. What are the major factors contributing to the flare-up of the recent tension over the East China-Sea?II. Factors behind the recent tension: The Sino-Japan relations have became more difficult due to the recent violent protest in Beijing after the Japanese bought the three islands over the disputed islands. Also, to respond back, China has increased their military activity around the dispute islands that led to the competition for gas field from both countries such as Japan and China. These three factors contributes to flare up of the recent tension over the East China-Sea. 2.1. Recent violent protest in Beijing The long-standing territorial dispute escalated dramatically when the three islands known as the Daioyu in China and the Senkaku in Japan were bought by a private Japanese owner for more than US$25 million (Taylor, 2012).This unlawful landing of the Japanese was violating Chinese territorial sovereignty (Lei, 2012). On September 2012, there was an Anti-Japanese protest as Chinese protestors have vandalized the Japanese embassy in Beijing (Badkar, 2012). The protests have spread throughout China and the Japanese embassy in Beijing was attacked with rocks, eggs and bottles (Moore, 2012). More than 1,000 protesters had burned Japanese flags, set fire and destroyed Japanese cars and companies. After the protests, Chinese government refused to apologize for the series of anti-Japanese protests (Watts, 2012) and says that the main problem was because of the Japanese government has done a series of things that have hurt the feelings of Chinese people especially in its treatment of history (Li, 2012). Whereas, Japan says the islands have been a part of its territory since the late 19th century and China had only shown interests over the territory after knowing the presence of potentially valuable natural resources (McCurry, 2012). In addition, Japanese government Shinzo also criticized Chinese violation against Japanese that it will only damage to Japanese-affiliated companies and Japanese nationals that have made contributions to the Chinese economy as China just want to achieve their political goal (McCurry, 2012). Furthermore, it only frustrates Sino-Japanese trade tie and lead Japan to shift investment to other Asia country. 2.2. Chinese military naval navigate in disputed islands In 2008, China and Japan have agreed on the United Nation conventional on the Law of the Sea in which both sides agreed to navigate in their territorial maritime. However, the military naval is not allowed to navigate in the surrounding of the Senkaku islands (Panda, 2016). After Japanese put three disputed islands under control of Japanese Government, China responded immediately by sending naval to navigate in the disputed islands. On 09 June 2016, China sent other military naval to navigate in the surrounding disputed islands (Ministry of Foreign Affairs of Japan, 2017). The area where forbade the navigation of military naval is called contiguous area. However, China always violates the agreement and sometimes send its huge military naval to reach the surrounding islands. Whereas, in Japan to response back to China, Japan have increased its defense and put radar system to capture the picture of Chinese naval when it navigates in disputed areas. Beside this, Japan has participated in the Malabar drill with United States and its allies, as its purpose to signal China that Japanese allies such as United States will defend Japan from foreign invasion, including Senkaku islands. Furthermore, Japanese Prime Minister’s speech has made clearly that no other state can use its bluff or military action to coerce the International Community to change the norm of Unclose (Ayako Mei, 2016). As Japan and China has showed muscle on each other, there is no best solution to remedy the status quo. Furthermore, the International Community have recommended the solution to solve the conflict peacefully, yet both sides still increase their expense on defense and military over one another (International Crisis Group, 2016). 2.3. The Contest for gas field Japan and China have made agreement on the natural resource in East China Sea on June, 2008, which both sides can extract the natural resource and pump gas in their respective area. China and Japan also agreed to have exclusive economic zones (EEZ), which both countries are not allowed to pump or extract natural resource. This area is known as the median line, which is the overlapping area where both sides claimed as their territorial maritime (JiJi, 2017). In 2010, Japan and China have made other bilateral agreements in joining pumping oil together in the disputed area. Also, Japan need to join pumping oil where China have already pumped. However, this agreement was never ratified because China claimed to draw the territorial water base on the continental shelf, whereas Japan demand to follow the exclusive economic zones (EEZ) (Szechenyi, 2015). On the other hand, in 2013 China have built facilities and sent its mobile drilling ships to extract and pump oil near disputed islands. Japan protested against China’s action and considered it as unilateral action that China have violated the agreement in 2008, which both sides have to be equally benefit from the natural resources in disputed areas. Beside this, Japan accused China for putting radar system on its mobile drilling ship for the advantage of military strategy (Jash, 2017). Whereas, for China to respond back to Japan, saying that China have the right to pump the oil from that area. According to the continental shelf, Japan is overlapped on the zones that belong to China; therefore, Japan should shortens its territorial maritime. Furthermore, China regards the demand of Japan to follows the exclusive economic zones (EEZ) as unilateral action as exclusive economic zones (EEZ) haven’t ratified yet. As the agreement came into controversial, Japan have responded to China by created an Air Identification Zone (AIZ) in East China Sea. Despite the increase of arms in both sides, China and Japan can also deal the conflict peacefully by following article 2 of United Nations.III. Conclusion In conclusion, Japan and China’s governments are trying to establish the control over the East China-Sea in order to extract the natural resources to improve their economy. In recent years, the tensions between Japan and China over the Senkaku/Diaoyu islands have risen due to the military capabilities, radar and missile systems. These factors make Japan and China facing a security dilemma as China’s security is Japan’s insecurity and Japan’s security is China’s insecurity. Even though, the leaders of Japan and China have avoided to control over the Senkaku/Diaoyu Islands, an action by local private companies from both countries could result in the unintended increased of enmity (Council Foreign relations, 2017). Furthermore, this tension also make nationalist sentiments rising and political distrust. In addition, Japan’s and China’s government will be preventing unintended escalation in the East China Sea by creating an atmosphere for dispute solving through bilateral meeting and agreements.