China has ordered its only aircraft carrier - the PNAS Liaoning - into the Senkaku island chain.

THREE days ago China declared a no-fly zone over waters claimed by Japan. Yesterday, the US flew bombers over them. Today, China has sent in an aircraft carrier. Are these the drums of war on our doorstep?

Late yesterday Australian time, two US B-52 bombers flew over the Senkaku/Diaoyou island chain in the East China Sea –a deliberately provocative act in response to a freshly declared “air identification zone”.

In response, China has ordered its only aircraft carrier - the PNAS Liaoning - into the disputed waters.

This afternoon, China's defence ministry said it "monitored'' the US B-52 bomber flights in its newly-declared air defence identification zone

In a statement China's defence spokesman Geng Yansheng said: "The Chinese military monitored the entire process, carried out identification in a timely manner, and ascertained the type of US aircraft.

"China is capable of exercising effective control over this airspace,'' Geng added.

The statement, China's first official response to the US action, appeared to be an effort to avoid confrontation while also asserting its authority.

The carrier battlegroup is destined for the Scarborough shoal, claimed by Manila and just 200km from the Philippines, last year.

Once there the warships will conduct "scientific experiments" and "military exercises" , the Chinese website sina.com.cn says.

It's a major escalation of tensions over several sets of islands which have been brewing for decades, but has reached boiling point in the past week.

The Chinese navy has announce the aircraft carrier has put to sea from the port of Qingdao with an escort of two destroyers and two frigates. It's destination: "Routine training exercises" that happens to be in disputed waters of the South China Sea.

“This is the first time since the Liaoning entered service that it has carried out long-term drills on the high seas,” an official Chinese naval website declares.

"Other nations do not need to be alarmed," said Zhang Junshe, an expert with the navy, in an interview with China's English language news agency Xinhua.

What is their significance?

The confrontations have all the “red flags” of impending conflict: Disputed territory. Powerful nations. Bluffs and counter-bluffs. Bravado.

It also has another vital ingredient: Gas.

The dispute over the Senkaku island chain is not new. And it is just one set of islands on the western Pacific Rim over which China and its neighbours have been bickering for decades.

Why? Probably because the adjacent waters contain as-yet untapped oil and gas fields.

Who gets to exploit these resources will be determined by who owns these islands.

On November 23, China threw fuel on the diplomatic fire that has been growing between it and Japan all year. It declared a new “Air Defence Identification Zone” over a broad swathe of the East China Sea. This happens to include the air over the islands Japan considers its own.

Chinese authorities have said any intruding aircraft are subject to "emergency military measures" if they do not identify themselves or obey Beijing's orders

US escalation

The unarmed US bombers took off from Guam yesterday as part of a "previously scheduled" and “routine exercise” in the area, US defence officials said.

A US official, speaking on condition of anonymity, confirmed to AFP the two planes were B-52 bombers.

``Last night we conducted a training exercise that was long-planned. It involved two aircraft flying from Guam and returning to Guam,'' Pentagon spokesman Colonel Steven Warren told reporters.

No flight plan was submitted beforehand to the Chinese and the mission went ahead ``without incident,'' with the two aircraft spending ``less than an hour'' in the unilaterally-declared Air Defence Identification Zone (ADIZ), Warren said.



A cascade of rising tensions

This is just the latest escalation. In the past year, more and more research vessels and – more ominously – warships have been deliberately sent into the disputed zone.

Japan suddenly “nationalised” the Senkaku islands in September. It was an open declaration that Japan considered the islands part of its “mainland” and would not tolerate any continued claims.

China was incensed. It immediately cancelled all official visits and imposed boycotts on Japanese products. It also sent ships and planes to the islands in a show of force.

In response, Japan mobilised vessels and aircraft, raising fears the tensions could trigger an accidental clash.

China's newly expanded air defense zone is just the latest development. The zone also includes waters claimed by Taiwan and South Korea, which also have both expressed their displeasure at Beijing's move.

Under the rules unilaterally declared by China, all aircraft are expected to provide a flight plan, clearly mark their nationality and maintain two-way radio communication to allow them to respond to identification inquiries from Chinese authorities.

This "overlaps" airspace over which Japan claims the same right.

"The air defense zone set up by Japan over the Diaoyu Islands is illegal, as the islands belong to China and the airspace over them is China's territorial airspace, rather than part of the air defense zone of another country," a Chinese navy spokesman said.

Now the United States has waded into the diplomatic game of high-stakes poker.

International reaction

Japan, the United States and several other governments sharply criticized China's move.

Australia earlier this week summoned Beijing's ambassador to express its opposition and Tokyo called on airlines to refuse to accept China's demands to abide by new rules when flying into the zone.

Pentagon officials said the United States views the area as international air space and American military aircraft would operate in the zone as before without submitting flight plans to China in advance.

Without taking sides in the territorial feud, UN Secretary General Ban Ki-moon meanwhile called on China and Japan to negotiate an end to their dispute.

Ban on Tuesday said tensions should be handled ``amicably through dialogue and negotiations.''