Vice President Biden has arrived in Japan today in the midst of that country's dispute over China's declaration of an expanded air defense identification zone. China's sudden declaration of an “ADIZ” over uninhabited islands has Japan and the US also flying military aircraft in disputed air space. With pilots potentially facing each other at high speeds, there's risk of a collision or a misunderstanding that could lead to unintended consequences. It's all about history and unfinished business from World War II, brought up to date by nationalism, economic competition and power politics. Is it really just between Japan and China? Has the US lost an opportunity to help forge a compromise by weighing in on the side of Japan?