China began the week by escalating tensions with all its neighbors, declaring an Air Defense Identification Zone (ADIZ) over islands belonging to Japan. Who this belligerence is meant to spook the most is still up for debate but, indisputably, the move poses its most major threat to the country south of the ADIZ: Taiwan.
China's use of an archaic military term over international waters has put a number of countries on high alert. The ADIZ, in the East China Sea, includes islands belonging to Japan and waters belonging to no country in particular. China declared unilaterally that, as of Saturday, aircraft must notify Chinese authorities if they are to fly in that region. If they do not, they are subject to "emergency" attack by the Chinese military. Both Japan and the United States expressed concern, and the United States actively challenged the declaration by flying in the region.
China responded to Japan's concerns about their islands by calling the statements "irresponsible." To America's far more active challenge, they had a more active answer: following the American and Japanese planes and identifying them. American and Japanese governments both said they were flying in the zone the way they would normally, entirely ignoring the new ADIZ. While the Chinese government has yet to attack those planes, they made clear they are aware of the intrusions and intend, in some way, to "enforce" their new regulation.
Naturally, the fact that the United States and Japan are flagrantly violating this unilateral decree has focused most of the controversy on their relationship with China. However, China's sovereignty claims pose a much less significant threat to Japan, a country with an island base for the U.S. military, than Taiwan, which the People's Republic still insists belongs to them. Wielding one of the few legitimate claims to sovereignty in the world (sorry Quebec, Scotland, the Basque Country, Catalonia, and Abkhazia), Taiwan more than any other country stands to lose if China's arbitrary decree of sovereignty over international waters is not challenged. And no one is more aware of this than the Taiwanese government.
Taiwan had been warning of impending Chinese aggression for some time this year. Last month, the Taiwanese Ministry of National Defense released a report predicting that China's maritime military operations could overtake the island and any outside defenses by 2020. As the United States is obligated by treaty to defend Taiwan of impending Chinese invasion, the report's claim that an attack from China would be "wholly sufficient" also takes into consideration a defeat of American forces.
A month later, China docked its only aircraft carrier, the Liaoning, on the island of Hainan—a short hop from Taiwan's other shore. With an aircraft carrier cozily harbored on one coast and a fleet of war planes colonizing international waters on the other, the Taiwanese government became rightfully concerned. Taiwan's deputy representative to the United States announced that the island nation had immediately expressed its concerns to the United States after having its National Security Council issue a statement reaffirming Taiwan's sovereignty over its land and surrounding waters. Taiwan made its official "stern protest" with China Friday.
As the conflict develops, the United States owes it to Japan, above all, not to yield to China's whim that they now own the airspace over Japanese islands. But Japan needs the U.S. far less than Taiwan does, and in the long term, it is this ally the United States' military strategy should strive to protect over others in the region, a country whose geography poses an unending existential danger. China is not one to use tactics independent of themselves without a strategy, and its movements on the seas recently can only be tied to one potential target: Taiwan.