The telephone conversation between Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping last Friday was something of a landmark because it was the first such contact between the current leaders of Asia's two biggest economies. The 40-minute chat, apparently initiated at the request of Mr Abe, came days before the trilateral summit between Japan, China and South Korea to be held tomorrow in Tokyo, to be attended by Chinese Premier Li Keqiang. Mr Abe will use that occasion to also hold bilateral talks with his visitors. More importantly, US President Donald Trump and North Korean leader Kim Jong Un are weeks away from holding the first United States-North Korea summit.

Mr Abe's outreach to Mr Xi, part of a reset of ties that he is attempting with China, was no doubt prompted equally by anxiety over being a mere bystander in the fast-paced developments surrounding the Korean peninsula. Having projected a special relationship with the US, including warm personal ties with Mr Trump, Mr Abe has looked askance as his powerful ally unexpectedly accepted a summit with Mr Kim just as he was himself pressing for tougher sanctions on North Korea. He now fears that Mr Trump, who has declined to let Japan off the hook in their trade dispute, will do a deal with Mr Kim that, while protecting US interests, may leave Japan vulnerable to North Korean aggression.