The standoff between Japan and China over the islands known as the Diaoyu in China and the Senkaku in Japan, is a toxic mix of two rising nationalisms and unresolved mutual resentments. Add to that the uncertain steps of the US, divided between its formal security obligations to Japan and its powerful economic ties to China, and the risks of an accidental conflict becomes uncomfortably real.
China and Japan have been prickly neighbours for centuries. China traditionally viewed Japan as one of its smaller, weaker, tributary neighbours; political satellites to China's sun. So when China's Qing dynasty declined in the 19th century and Japan transformed itself into a successful modern nation that held up a mirror to China's failures, China's reformers and revolutionaries flocked to Japan to try to learn its lessons. If Japan could become a strong power, they asked, why was China weak?
This question dominated the unhappy history that followed. In 1895, Japan occupied Taiwan, intending to turn it into a model colony, the first step to the domination of Asia. In the 20th century, Japan invaded Manchuria, and finally China itself, in a brutal eight-year war of occupation, that ended only with Japan's defeat by the allied powers in 1945.
Nowhere is Japan's aggression remembered more clearly than in China. Chinese history, as the Communist party has constructed it since 1989, blames all of China's ills on external aggression – a humiliation that China's Communist party has pledged to expunge. Western powers have minor roles in this narrative, but Japan is the star of the story. Each 18 September, on the anniversary of the Japanese bombing of a Japanese railway in Mukden that became the pretext for the occupation of Manchuria in 1931, China revives that legacy in National Humiliation Day, an exercise in ritual victimhood designed to shore up its own political credentials. History was not always told this way: from the Communist victory in 1949 until the death of Mao Zedong, the Communist party's main political target was the Kuomintang, Taiwan's ruling party and Mao's rivals for historical legitimacy.
In the past China routinely published maps that showed the disputed islands as Japanese and referred to them as the Senkaku. But after the trauma of Tiananmen Square in 1989, China's rulers needed nationalism to justify their continuing rule, and began to memorialise Japan's atrocities in new sites across the country. In April this year, China's foreign ministry escalated its claim by describing the Diaoyu islands as a "core" national interest, on a par with Tibet or Taiwan. Indignation and resentment have their political uses.
China, like many of its neighbours, believes that Japan has shown insufficient remorse for its past aggression. Japan's victors in 1945 left the Japanese emperor on his throne and the country relatively unpurged of past attitudes and ideology. But while others have made their peace in the interests of the future, China has installed Japan's crimes as a central narrative of its modern identity. The symbolic value of the Diaoyu/Senkaku islands is now embedded in an unpredictable contest of national pride.
In such games, small escalations have disproportionate effects. Japan argues that ownership of the islands is not in dispute and has a powerful historical and legal case. For Japan, too, they have become a touchstone of national pride and both governments are held prisoner by a popular sentiment they have done much to create.
So when China declared its East China Sea Air Defense Identification Zone (ADIZ), it was no surprise that it was read as an escalation of its claim to sovereignty that obliged both Japan and the US to respond. Many countries, beginning with the United States, have declared large ADIZs that require planes crossing the zone to file flight plans and report to air traffic control. China can plausibly argue these precedents as justification, but, as Beijing well knows, to declare an ADIZ in a situation of tension, with no prior consultation, and to apply the rules to all traffic regardless of its destination, elevates it far beyond the routine. Few doubt that China intends this as an enforcement of its claim; an ill-advised move with potential consequences that nobody can foresee.