China and Japan have been engaging with the United States so extensively - as a collaborator and a protector, respectively - that they have neglected to invest in their mutual relationship, beyond formalities. The deficit is unnatural for neighbours which share a common philosophic wellspring in their ancestry, and thriving trade and investment in their modern development. The omission is getting dangerous, as shown in the islands dispute threatening international peace.
Neighbours identify specific issues so as to work out a solution, and these two haven't. Inattentiveness towards the relationship, whether by design or as a result of unresolved animus, will be disastrous all round. Even if this had been understood in Beijing and Tokyo, it was ignored, it appears, as a matter of policy.
This is why the meeting in Beijing last week between President Xi Jinping and Prime Minister Shinzo Abe was notable despite the negative vibes. With no unfortunate incidents and goodwill on both sides, it may halt a slide towards confrontational tendencies. This is illustrated in the reference to communication mechanisms to be set up to avert accidental hostilities over the islands' disputed ownership, and renewed contacts between ministers of the two countries.
No one can be confident the meeting was an ice-breaking moment but the diplomatic symbolism did carry weight. But for Mr Xi being the host of the Apec meetings, which bore protocol obligations he could not avoid, the meeting might never have happened. The gap in understanding had been that wide.
It is thus too much to expect that Chinese anger over the Japanese ruling elite's habitual distortion of wartime events will evaporate, just like that. Mr Abe is among Liberal Democratic Party grandees and new-generation leaders whose words and deeds concerning the past and Yasukuni will be watched in Beijing for evidence of sincerity, now that both nations have aspired to overcome differences in a spirit of "facing history squarely and looking forward to the future", as the Chinese authorities put it. Alas, an emerging United States-Japan-Australia security axis will not be well received in Beijing.
But neither can Japanese fears about China's intentions be set side. China has to rein in its enthusiasm in legitimising an ownership contest. This is the test of intent for both nations. Given the conditions, confidence boosters are necessary to build an accommodation. It is not time yet to speak of trust between them. But as a means of strengthening the diplomatic bulwark, a pact agreed upon prior to the Xi-Abe meeting complements four existing documents that have been the basis of China-Japan relations since normalisation of ties in 1972. Diplomacy beats staring daggers at each other.