TOKYO – The good news is that there won’t be a new war in Asia. The bad news is that the old one never really ended. And with Japanese and foreign patrol boats firing water cannons at each other this week, it may not be long before the real shooting resumes.

“The dispute over the Senkaku Islands is a direct legacy of the Pacific War. For many people, particularly in China, that war is still going on,” says Liu Jie, professor of history and international relations at Tokyo’s Waseda University.

Liu was among a dozen historians who converged on Tokyo this week to take a new look at the 15-year conflict that ended – or seemed to – with Japan’s surrender in August 1945. The consensus is grim: Nearly seven decades later, wartime adversaries share little agreement over how the war started, who was responsible or how to bury grudges that remain very much alive....