China's designation of an air defence identification zone (ADIZ) over the East China Sea serves both tactical and strategic motives.
Tactically, it is the logical outcome of Beijing's long-cherished intent to breach the "first island chain of defence", a string of major archipelagos off China's coast. They include the Japanese archipelago, Taiwan and the northern Philippines.
Beijing has long feared that rival powers could restrict its growth as a naval power by controlling or blocking key waterways in the area.
The United States and Japan, for instance, have frequently conducted joint military exercises in the Miyako Strait, one of the few international gateways into the Pacific Ocean for the Chinese navy.
Now, by marking its new ADIZ from the mainland coast to the Miyako Strait, China has unilaterally proclaimed a self-endowed right to patrol this area, so as to provide early warning against unfriendly aircraft.
This will greatly enhance the ease of passage of its warships to the Pacific Ocean. Military experts say that in modern warfare, any aircraft carrier would become a sitting duck without such a zone.
Strategically, the ADIZ announcement is China's attempt to assert its position as a key player in security matters in this region that is commensurate with its economic pre-eminence.
While China does not seek to edge out the American presence in the West Pacific, it wants a role for itself that commands attention from its neighbours.
Mr Zhou Fangyin, director of the Institute of Global and Peripheral Strategy of the Chinese Academy of Social Sciences, pointed out that the relative economic influences between China and the US have completely reversed in the last five years.
In 2006, the US was the largest trading partner of 127 countries and China of only 70. By 2011, this situation had been reversed, with China being the largest trading partner of 124 countries while the figure for the US had dwindled to 76.
This change in the balance of economic influence is particularly true of the East Asian region. Of the US allies in this region - Japan, South Korea, the Philippines and Australia - all but the Philippines has China as their largest trading partner.
Yet, on security matters, it is still the US that calls the shots in the region. This situation is undesirable from the Chinese point of view.