These developments are based on tactical calculations on both sides, rather than fundamental changes in the two countries’ attitudes towards each other. Faced with an unpredictable international environment under the Trump administration, Tokyo and Beijing believe it is prudent to reduce unnecessary risks of confrontation. Though bilateral issues such as the Senkaku/Diaoyu Islands dispute are far from being solved, Beijing and Tokyo are willing to pursue high-level political exchanges to achieve tactical detente.

This trend towards improved relations began in early 2018. In mid-April, both countries resumed high-level economic dialogue for the first time in eight years. Before that, Tokyo’s repeated suggestions to restart bilateral talks had been rebuffed by a cautious China. China shifted its stance sharply early in 2018 and agreed to reopen dialogue.

As another sign of positive change, on 4 May Chinese President Xi Jinping had a telephone conversation with Abe for the first time. The call was followed by Chinese Premier Li Keqiang’s visit to Tokyo, which marked a significant turning point in Japan–China relations: it was the first visit of a Chinese premier to Japan since the nationalisation of the Senkaku Islands in 2012. During the May visit, both sides agreed to launch a long-awaited maritime and aerial communication mechanism — crucial for avoiding unintended conflicts in the East China Sea.

During his visit to Tokyo, Premier Li stated that ‘it is safe to say that Sino–Japanese political ties are returning to normal’. Japan took this remark as an official statement by China that ‘winter’ was over and ‘spring’ had arrived between Beijing and Tokyo.

It is important for Japan and China to accelerate the positive trend to ensure bilateral relations do not cool again, especially during times of increased uncertainty or tension. A touchstone of the improved relationship will be whether mutual visits by Abe and Xi are realised before the end of 2019.

Since nationalising the Senkaku Islands, no Japanese prime minister has visited Beijing except to attend international conferences. According to Japanese sources, discussions are ongoing for Abe to visit China in October 2018, which would coincide with the 40th anniversary of the peace treaty signed by both countries. Japan hopes Abe’s trip will pave the way for a reciprocal visit by Xi to Japan in 2019, which would be the first by a Chinese president since 2008. If these mutual visits take place, it will show that China–Japan relations are back on track.

At present, this scenario seems likely unless some serious incident occurs, such as collisions between the two countries’ vessels near the disputed Islands. Trade war between the United States and China is intensifying, with little prospect of compromise on both sides. On the security front, the Trump administration is poised to push forward its Indo-Pacific strategy to counter China’s Belt and Road Initiative. These situations will motivate Beijing more — not less — to improve its relations with Japan.

It is still unclear if this tactical detente will lead to stable and cooperative relations between the two countries in the medium to long term. Things do not look too optimistic. There are undercurrents of future crises in the East China Sea.

China constantly sends its coast guard vessels to Japan’s territorial waters surrounding the Senkaku Islands. Though China has tended to avoid provocative action in recent years, Japan is concerned that China will gradually increase the number of vessels sent to those areas. China also transferred administrative control of its coast guard from civilian to military authority in July. This move may lead to more tension.

China also continues to explore oil resources in the East China Sea near a median line that was proposed by Japan to separate their exclusive economic zones (EEZs). Japan has repeatedly appealed to China to stop unilateral oil exploration there, as the gas field underneath the median line overlaps both countries’ EEZs, but China has not ceased those operations.

The balance of power between the two countries is shifting rapidly in Beijing’s favour. China’s GDP has already grown to about triple that of Japan and China’s military budget is more than three times bigger. If these trends continue, it is likely that China will become even less willing to compromise in the East China Sea and adopt increasingly assertive behaviour towards Japan.

There are three ways that Japan could respond. The first is to keep making ‘salami slice’ concessions on issues in the East China Sea to maintain detente with China. The second is to confront China and push back by drastically increasing its defence and coast guard capabilities.

Neither of these paths is realistic. Politically, it is very difficult for Japan to compromise on issues related to its territory and sovereignty. At the same time, budget constraints alone make it difficult for Japan to counter China’s military expansion on its own.

The third and most realistic choice is somewhat between the first and second: to deter China with the United States and other partners, while deepening bilateral ties with China. Japan could deter China’s assertive behaviour more effectively if it cooperates with other countries, which share the same concerns. It may also induce China to improve and deepen its relations with Japan, in order to avoid encirclement by those countries.

Japan is already accelerating efforts on the deterrence front. Under the new guidelines for Japan–US defence cooperation, the two nations are working together to further strengthen their alliance. Japan is also seeking to expand its maritime security cooperation with Australia, India, France and the United Kingdom.

On the other hand, Japan’s efforts to increase engagement with China are lagging. It is important for Japan to use the present detente period for this purpose. In addition to high-level exchanges, Japan should deepen economic cooperation with China, not only bilaterally but also within multilateral frameworks such as the Regional Comprehensive Economic Partnership (RCEP).

Easing the tensions between Japan and China would benefit the whole Asian region. Not only would it reduce the risk of conflict but it would also make it easier to promote economic cooperation.

It is also crucial for Japan to establish crisis management mechanisms with China so that existing issues in the East China Sea do not develop into a serious confrontation or conflict. On 8 June, Japan and China implemented the bilateral maritime and aerial communication mechanism. This is a start but more needs to be done.

Unlike the United States and China, Japan and China do not have a hotline connecting both countries’ senior defence officials. Regular exchanges between Japan’s Self-Defense Force and China’s People’s Liberation Army have been suspended. Now is a good time to try and rebuild these much-needed communication frameworks.

Hiroyuki Akita is foreign and security affairs commentator at Nikkei.

This article appeared in the most recent edition of East Asia Forum Quarterly, ‘Peak Japan’.