TOKYO – Vice President Biden urged Japan and China last week to set up “effective channels of communication” to avoid a dangerous escalation in their increasingly tense dispute over maritime territory. But the estrangement between the Asian powers is so deep they are barely talking.

Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping, both in office for roughly a year, have spoken just once – for a matter of minutes. The Japanese and Chinese foreign ministers haven’t held formal talks in 14 months. Contact between their coast guards and militaries is zero.

“There used to be so many channels” of communication, said a senior Japanese Foreign Ministry official, speaking on the condition of anonymity to discuss sensitive information. “But that has all but stopped.”

The decline in high-level contact, the most pronounced since Japan and China normalized relations 41 years ago, points to fundamental shifts in both countries that have made it harder for diplomats to control and solve problems. In particular, hardening nationalism in both China and Japan has reduced the ability of officials to appear conciliatory, and Japanese Foreign Ministry officers who appear to be sympathetic to China have been largely sidelined over the last 12 years, according to two former senior-level officials who handled Asian affairs.

Several current and former Japanese diplomats emphasized that both sides are responsible for the current chill. China, they say, appears to increasingly value demonstrating its military strength, even at the risk of causing discord. The Chinese Foreign Ministry – the one official channel open to Japan – has little sway with members of the more powerful military and Politburo.

Japanese officials say it is increasingly difficult to talk to the Chinese decision-makers, even through the secretive back channels that were once a staple of relations.

In recent months, even the most basic attempts at agreement have fallen apart. Officials on both sides say they’re interested in dialogue, but China says it should only happen after Japan acknowledges that the uninhabited rocks it controls in the East China Sea are indeed disputed. Japanese officials say their claim on the rocks is so incontrovertible that no dispute exists. The feud over the rocky islands – known in Japan as the Senkaku Islands and in China as the Diaoyu Islands – escalated after China declared an “air defense identification zone” over them last month.

“The situation now is that both sides are embroiled in conflicts, and they pretty much insist on doing things their own way,” said Liang Yunxiang, a specialist in China-Japan relations at Peking University’s School of International Studies.

Relations between Beijing and Tokyo have long been fraught, due to the memories in China of Japan’s brutal invasion and occupation beginning in the 1930s.