Over the past two years, several clashes took place in the seas of China and Japan. Many coastal states seek to appropriate the wider maritime areas, not only to assert their power, but also for their economic development. The stakes are considerable: the largest ports in the world are found in the region (Shanghai, Tianjin, Hong Kong among Chinese ports), Singapore, Pusan, and those of the Japanese megalopolis. Economic activities such as transport of goods, fishing, the eventual discovery of hydrocarbons are directly related to maritime space consequently.
Japan, whose area is equivalent to the one of Italy, is the world’s largest 6th State if one takes into account its maritime space.
Current issues of maritime boundaries in Asia reactivate unsolved historical tensions, notably the resentment of Asian populations has for the massacres committed by Japan during World War II. China and Korea (North and South ) remember Japan has conquered their territory in whole or in part in the first half of the twentieth century. As for Japan, the goal is to demonstrate its power over China that went recently before him on the economic level.
See the interesting presentation of maritime issues in the region made by the American Congress (with some very good maps):
Picture: Drawings of kids on an area highway between Osaka and Tokyo.