Annoyed with a US president who simply seems to change policy at whim, the Japanese prime minister plans to see China’s leader for a one-on-one discussion. This isn’t a description of the sudden warming of relations between Shinzo Abe and Xi Jinping over the past few days. It happened in July 1971, when president Richard Nixon announced that he would visit China without having first warned his closest Asian ally, Japan, an event that became known as the Nixon “shock”.

Wasting little time, prime minister Eisaku Sato began his own overtures to China. His eventual successor, Kakuei Tanaka, visited Beijing in the autumn of 1972, just a few months after Nixon. From that point, Japan felt put on notice that it would have to chart more of its own course in foreign policy.

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This week, there has been wide coverage of a new warmth in the relationship between China and Japan. The chilly looks and words between Abe and Xi of just a year or two ago seem to have been replaced by a flurry of visits and plans for visits. The Chinese president and Japanese premier recently spoke on the phone for the first time and Chinese Premier Li Keqiang has just finished a three-day tour of Japan, the first by a major Chinese leader since 2010, during which he met the Emperor. With the relationship between the two sides still sensitive because of unreconciled issues over Japanese crimes during the second world war, this is a startling development indeed.

Yet it needs to be seen from both a short- and long-term perspective. In the short term, there is one reason why China and Japan might need to be on the same page: Korea. Nobody quite knows where the current negotiations may go, but there seems to be an unease both in Beijing and Tokyo about their two capitals being cut out of the loop while a maverick DC establishment cuts a deal with both Koreas.

There are supplementary reasons too. With much of the rest of the world, Tokyo and Beijing sit in the same place when it comes to wanting to preserve the Iran nuclear deal. But compared to Europe, China and Japan stand to suffer more if that deal falls through. The North Korean talks could stall if, having seen Trump reverse Washington’s position on the Tehran deal, Pyongyang decides it cannot trust the US to keep to its word.

Yet warming and cooling is nothing new in the Japan-China relationship over the past half-century. That 1972 “Nixon shock” seemed like a very big deal to the Japanese at the time, leading Sato and Tanaka to reach out to China to show they were capable of independent diplomacy. Within a short time, tempers cooled. The US-Japan relationship remained a strong one; a decade later, Ronald Reagan and Yasuhiro Nakasone would develop one of the strongest relationships of the cold war era.

The underlying reason was the same then as now: the US and Japan needed each other in terms of preserving a liberal political and strategic order in East Asia. They had a commonality of basic interests against the USSR. China was a partner, a balance against the Soviets, in those days, but an ally of convenience for the US and Japan rather than a friend because of shared mutual values.

Over the post-cold war decades, there have been periods of warmth between Beijing and Tokyo. Abe’s first brief premiership, in 2006-7, was also marked by a rapprochement with China (ironically, as Abe then became the butt of Chinese ire in the first part of his current premiership, which began in 2012).

That perspective is needed to understand the new, more positive language of the last few days. It is very good news that China and Japan are speaking respectfully to each other once again. The behaviour of the two biggest economies and military powers of the region shapes the tenor of everything from Siberia to Tasmania.

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However, a rapprochement over Korea, even if it emerges, doesn’t solve fundamental issues. China is seeking to create an order in the region in which its economic and military structures have much more authority. Japan is content with the status quo and worries that its freedom to operate will be constrained by a more powerful Beijing. China would like the US to have a much less prominent role in the region, or even to withdraw. Japan very much wishes the US to stay in the region, even if it is unsure about the reliability of its current leader: hence its desire to keep the Trans-Pacific Partnership alive, even without the presence of the US. The warmer winds blowing across the East China Sea are genuine. But they don’t solve the long-term issues of what a new regional order might look like.

Rana Mitter is Director of the University China Centre at the University of Oxford and author of A Bitter Revolution: China’s Struggle with the Modern World and China’s War with Japan, 1937-45: The Struggle for Survival