The Diaoyu Islands. [China.org.cn]

"After stealing the islands, Japan may further ask for an exclusive economic zone of 200 nautical miles and may take the Diaoyu Islands as the base to divide the continental shelf of the East China Sea and further ask for the relevant oil and gas resources," said Zhang Haiwen, associate director of China Institute for Marine Affairs under State Oceanic Administration of China.

Geo-politically, the Diaoyu Islands have a huge strategic and military value. The islands are at the first island chain in the West Pacific, and are a springboard for entering China from the outside sea." If Japan controls the waters, it means Japan has clutched the throat of the channel in which China goes to the open sea of the Pacific," said Zhang.

Why Japan's excuses are invalid?

In order to possess the Diaoyu Islands, the Japanese government has made up many excuses.

Excuse one: The Diaoyu Islands were a land without owner, and according to the "occupation first" principle, the one who occupied them first should have them.

The associate director of Research Center for Chinese Borderland History and Geography under Chinese Academy of Social Sciences Li Guoqiang said that the Diaoyu Islands had no residents in the past, but it does not mean they were "a land without owner." In fact, in as early as the Ming Dynasty, the Diaoyu Islands were already regarded as a marine defense zone and governed by the Ming government.