The ownership of the islands is distorted and disputed by war and history. Taiwan has also laid claim to them. On their own, there is little besides a dangerous brand of nationalism to justify the depth of the dispute about the islands. But, the islands may well lie on or close to significant reserves of oil and gas, which can provide a vital boost to the economies and energy security of the competing nations.-gulfnews.com

another source:

http://gulfnews.com/opinions/editorials/japan-china-must-defuse-dangerous-nationalism-1.1063945