While Japan's rivalry with China in the East China Sea is currently limited to competition over underground gas, pundits are fretting a more worrying possibility -- a real conflict between the two major players.
Even if the countries do not mean to start a military clash, incidents in the sea could spin out of control, given the combination of distrust and lack of communication between the two countries, analysts and diplomats say.
"Incursions by Chinese planes and subs into Japanese waters are occurring more frequently," said Bonnie Glaser, senior associate at the Center for Strategic and International Studies in Washington.
"When ships and planes operate in close proximity to one another, the danger of an accident increases. Avoiding such an accident requires clear knowledge of both sides' rules of engagement, and I am not confident (the two countries have that)," she said.