'East Asia is trapped in a vicious cycle of escalating tensions, with China's rising power giving Japanese hawks legitimacy in their bid to bolster the military -- exactly what Beijing says it fears.
The United States -- rival to one power, ally to the other -- finds itself walking a tightrope, with Vice President Joe Biden in China this week urging restraint to "reduce the possibility of crisis or mistake", according to a US administration official.
But that is hard when relations between Asia's two biggest economies are so poisoned by history. Every time Beijing summons the demons of Japan's past aggression, Tokyo plays on fears of Chinese domination to come.
"This is a battle about pride," said Takehiko Yamamoto, international security professor at Japan's Waseda University. "I cannot, for now, see there being any compromises."
Simmering tensions heated up with Japan's September 2012 purchase of some of the Tokyo-controlled Senkaku islands, in the East China Sea, from their private Japanese owners. China, which calls them the Diaoyus, regards them as its territory.
Since then, China has sent ships and aircraft into the area on scores of occasions, prompting counter-deployments by Japan, and last month Beijing declared an Air Defence Identification Zone (ADIZ) covering a large stretch of the East China Sea.
Japan already has an ADIZ, which now overlaps China's. In October, a Chinese drone flight prompted Japanese threats to shoot down unmanned aircraft that enter its airspace, something Beijing said would amount to "an act of war".'