relation between two countries

Year 2018 could be a turning point for China and Japan, since the 2012 when Japan provoked the Diaoyu Island dispute. In May 2018, eight years until the last time Chinese prime minister visited Japan, primer Li Keqiang visited Japan officially and the visit is highly valued by both countries. The seventh China-Japan-ROK summit meeting was held in Japan recently. Sino-Japanese relationship is eased. From Japanese side there are mainly three reasons for devotion to improve relations with China.
The most immediate impact on Sino-Japanese relation actually comes from America. Trade protectionism that America is implementing prompts Japan to turn its direction in order to ensure its economic security. China, Japan and South Korea are now consulting and planning for the free trade zone. In history, America has the measures to destroy the free trade process of the three countries, which is obviously not in their interests. Except that, the latest U.S steel and aluminum tariff policy even deliberately aimed at Japan, which deepened the mutual distrust.
Since Trump administration sticks to the opinion that the overwhelming economic advantage is more crucial than the political game, Japan tweaks its strategy adaptable. In the past, America created opinion pressure on China while now it tries to provoke trade war frequently. During the period Chinese meets obstacles in Sino-US trade, Japan attempts to expand its market share in China and takes advantage of the Chinese demand. Shinzo Abe, the Japanese prime minister, has also expressed that there will be a vast potential for future development in AI, digital economy and infrastructure fields if it establish cooperation with China.
The fundamental reason for ease is Japan and China have both achieved political goals in the past eight years. Japan has assisted with the Asia-Pacific rebalance strategy. Japan has lifted the right to collective self-defence. Later it revised the U.S-Japan defense policy. China demarcated the east China ADIZ (Air Defence Identification Zone) and strengthened the protection of the south China sea. In the meantime, levels of their strength keep approaching to each other. China has grown into a strong entity that in which manner has diplomacy with China is an unavoidable issue for Japan. More than that, BRI (the Belt and Road initiative) that built by China produces positive effects in the area covered. The substantial prospect of joining BRI prompts Japan to shift its position.
An important underlying reason for the relationship changing is that Japan is also under the threat from its neighbor North Korea as well as America. For being marginalized on North Korea nuclear issue, Japan will be threatening if North Korea comes to an agreement with America by abandoning only the long-range missile develops. As neighbouring country and powerful country, China is becoming more crucial in Japanese regional strategy. For another thing, both countries have no intention to stir up or fully prepare for war, especially with the intimate geographical relationship between them.
Take together, the beginning to thaw in Sino-Japan relations is an outcome of change pattern of China, Japan and America. It results from Japan weighted pros and cons and will offset some of the negative effects of Sino-America trade war. The clear understanding that Japan and America are powerful supports for each as a long-term trend, should be maintained.
中美贸易战，有利于日本。

中国对美贸易的受挫，有利于日本趁机扩大在中市场份额。

且本身中国市场就有足够的吸引力，另外日本原本在中国有大量投资。

中国的一带一路战略等等。

( Chinese market is attractive and valuable enough for Japan. Different from many western countries’ continuous criticize on Chinese economy development, Japan )
美国的贸易保护主义有打击到日本经济的危险，既有美国自身的贸易保护，也有因而导致的对中日韩自贸协定的破坏。

日本此举以求有备无患和增加对美筹码。

朝核问题中日本被边缘化，有必要改善同中国这个关键国家的关系。

( Japanese government’s unclear attitude towards aggression against China and keeping up with the pace of the U.S caused a long term tension between two countries. 删除)
Not only China but also Japan is benefit from globalization,
Sino-Japan relation can be analyzed in the Sino-America relation formerly.。