Long standing dispute over airspace . Now Tokyo decides to single handedly increase the area under its control. Protests in Taipei. Experts: the decision follows Taiwan’s improved relations with Beijing, with which Tokyo is competing for territory and riches.

Tokyo (AsiaNews / Agencies) - Japan has expanded its Air Defense Identification Zone (Adiz), the space that the aircraft of other states can not fly in without being identified, near Taiwan in the East China Sea, without first consulting with Taipei. The Taiwanese government has denounced the move as a "matter of national sovereignty." Experts speak of pre-emptive move by Tokyo in reaction to the rapprochement between Taiwan and Beijing.

The usual boundary between the air spaces of Japan and Taiwan is a small Yonaguni island, the westernmost island off Japan’s coast just 180 km from Taiwan. During World War II the United States determined that the airspace above the island was two-thirds Taiwanese and one third Japanese. On June 26, Tokyo shifted its area 22 km to the west.

Analysts point out that Japan may be right to ask that the bordering line does not pass over its island territory, but an intermediate point between the two territories, but that this unilateral decision is a reaction to the rapprochement between Taiwan and Beijing. Tokyo and Beijing have always been rivals in the East China Sea and are still discussing their borders. The area is rich in oil and gas reserves as well as for fishing and has great strategic importance.

Since the 80's Beijing has exploited the rich gas fields in the Xihu depression, which supplies Shanghai’s household and industrial needs. Japan protests that China that is "stealing" resources that fall within its territory.

The area near Okinotorishima, Japanese island 1,700 kilometres south of Tokyo is also contended. Beijing considers the island a mere rock is not suitable for human life and Chinese naval vessels have appeared in the area at least 3 times in the last 18 months. The island is considered to have underground resources, but above all, is halfway between Taiwan and Guam, home to a major U.S. military base.

Japan controls the Diaoyu Islands (called Senkaku by the Japanese), claimed by Beijing, which have reserves estimated between 3 and 7 billion tons of oil and allow fishing for an annual catch of 150 thousand tons. They are also of great military importance given their position. The Japanese navy patrol the area daily and the nearby islands Kume and Miyko are home to radar stations that monitor the area around the Diaoyu. But Chinese ships and planes are often seen.

The control over the entire island of Yonaguni would allow Tokyo better control of the Diaoyu Islands and other disputed areas.

Experts say that the issue between Japan and Taiwan is not new but so far the parties had tolerated it. Only after the recent rapprochement between Taipei and Beijing, a first but significantly step after decades of total closure, Tokyo has changed the situation. Drawing a heated protest from the government of Ma Ying-jeou, even though - experts say - perhaps Taiwan is concerned not so much by its strategic situation or public reaction, but not to be seen as too compliant by Beijing. Precisely because of this the Taiwanese opposition has commented that the Sinophile policy of Ma not only distances Taiwan from Washington and Tokyo but wants to use the Adiz issue to arouse anti-Japanese sentiments to satisfy Beijing.