Tensions in the East China Sea escalated on Wednesday after the Chinese government said it had monitored two American B-52 bombers that flew over its new air defence zone, but had decided not to take any further action.
Beijing published co-ordinates for the maritime air defence zone over the weekend, threatening “defensive emergency measures” against any aircraft that fly through the area without identifying themselves and following Chinese instructions.
The zone covers most of the East China Sea, including a tiny archipelago known as the Senkaku in Japan and the Diaoyu in China, and is clearly aimed at undermining Japanese administrative control of the islands.
Tensions have been ratcheted up in the region amid fears that Beijing may move to back its territorial claims in the area with military muscle, and vigorous enforcement of the zone could be a first step to more dangerous encounters.
“We need to stress that China will identify every aircraft flying in the air defence identification zone according to the country’s announcement of aircraft identification rules for the air defense identification zone,” defence ministry spokesman Geng Yansheng told the official Xinhua news agency.
The Chinese army had monitored the entire process, carried out identification in a timely manner, and ascertained the type of aircraft. “China is capable of exercising effective control over this airspace,” he added.
Mr Geng said the US aircraft flew south and north along the eastern border of the zone, around 200 kilometres to the east of the Diaoyu Islands, for two hours and 22 minutes. Beijing is involved in bilateral disputes with its maritime neighbours over islands in the South China Sea and East China Sea, but one of the most tense is the standoff with Japan over the islands.
The row flared up in earnest in September 2012 when Japan nationalised three of the islands. Washington, which has hundreds of military aircraft based in the region and is boosting its presence in Asia as part of its Asia Pivot plan, has said it has no intention of complying with the new Chinese demands.
Tokyo has called the zone invalid, unenforceable and dangerous, while other stalwart US allies in the region, including Taiwan and South Korea, have also rejected it. The US described the B-52 flights as a training mission and said they were not flown in response to China's move to assert its claim of sovereignty over the Senkaku/Diaoyu islands. Officials in Washington said the two bombers took off from their home base in Guam around midday and were in the zone that encompasses the disputed islands for less than an hour before returning to their base, adding the aircraft encountered no problems.
Meanwhile there was angry reaction online, with parallels drawn between the overfly and the 2001 collision between a Chinese fighter and a US surveillance plane in international airspace off China's southeastern coast. The outspoken retired Major General Luo Yuan, who is extremely hawkish on relations with Washington, said the xone must be enforced with military might if necessary.
“No country must think that they can harbour the idea of leaving things to chance,” he wrote on his Weibo account. “If they refuse to comply, and act wilfully despite advice to the contrary ... China’s armed forces will take emergency defensive measures.”
