When China marked out an expansive swath of airspace above the East China Sea and effectively claimed it as under its control, it was seen as an abrupt escalation of an already tense territorial dispute.
The unilateral declaration last Saturday came accompanied with a map, geographic co-ordinates and an ominous warning: aircraft entering the "air defence identification zone" must notify authorities of flight plans and maintain radio communication - or risk "defensive emergency measures". The rules would take effect immediately.
Heated words and formal protests were swiftly volleyed at Beijing from other powers in the region including Japan, the United States and South Korea. And, in a surprise to some, the Australian government, took the calculated diplomatic step of calling in Ma Zhaoxu, the Chinese ambassador, to voice its concern.
What followed next might well have been outside China's calculations. In an audacious series of baiting and provocation from among the world's most powerful armies, first the US and then Japan and South Korea flew military aircraft through the disputed airspace without informing China.
Observers by now were wondering if China had made a strategic blunder. By ramping up the rhetoric, it had galvanised its rivals in the region, who appeared to have called Beijing's bluff.
China responded on Thursday by deploying its fighter jets and an early-warning aircraft to carry out "routine patrols". Air force spokesman Shen Jinke said the country's air force would remain on high alert and would deal with all air threats to protect national security.
The brinkmanship has ratcheted tensions up to a point that any miscalculation could trigger armed military confrontation.
Joe Biden's visit to China, starting on Sunday, has taken on global significance, with the US Vice-President expected to press China over its "unsettling" behaviour. A visit from Australian Foreign Minister Julie Bishop is also expected next week.
"Basically with Japan provoking, China reacting and now the US pressing, the risk of conflict progressively rises," Wang Xiangsui, a retired senior colonel of the People's Liberation Army, said.
"I think it's extremely unwise for these three economic powers to use military might to intensify the issue. But it's not Chinese planes flying to Seattle or San Diego - it's them who are flying here.
"And you still want to talk about co-operation? Of course this is impossible."
Down at sea level, at the heart of the dispute, is a clump of desolate, rocky and uninhabited islands controlled by Tokyo, known as Senkaku in Japan and Diaoyu in China. Taiwan also lays claim to the islands.
"Before 1971, neither China nor Taiwan made any claims over the Senkaku Islands ... neither government expressed any objection to Japanese sovereignty over the islands," said Tadashi Ikeda, a former deputy vice-minister at the Japanese foreign ministry, now a scholar at Ritsumeikan University.
That changed when a geological survey found rich deposits of oil under the seabed, which have become progressively more lucrative with technological advances and global energy security concerns.
If China was testing the strength of America's resolve to maintain its presence and alliances in the region, Beijing soon had its answer.
Within hours of the announcement of the new air defence zone both Secretary of State John Kerry and Defence Secretary Chuck Hagel condemned the move.
"This unilateral action constitutes an attempt to change the status quo in the East China Sea," Mr Kerry said in a statement issued from Geneva where he was locked in talks to suspend Iran's nuclear program.
On Tuesday two unarmed American B52 long-range bombers took off in Guam and flew in a long arc through the zone in a direct challenge to China's claim.
The administration's forceful response has been well received in America. It even earned praise from the hawkish Republican senator John McCain, who recently called his former friend Mr Kerry "a human wrecking ball" for his diplomatic efforts in the Middle East.
In Chinese eyes, the change in the status quo came well before last week. In September last year - just before President Xi Jinping took power - the Japanese government effectively nationalised three of the islands by buying them off a private landowner.
In April, the Chinese government indicated for the first time that it regarded the Diaoyu Islands as a "core interest" - a politically loaded term typically reserved for its most sensitive concerns, including Tibet, Taiwan and the restive far-western Xinjiang province.
The rising tensions in the East China Sea have coincided with Washington's strategic pivot - or what it is now calling a "rebalancing" - towards Asia in what many consider a move to contain the rise of China.
"The reason why we're seeing the tensions we're seeing has everything to do with the fact these islands have become pawns in a very high-level jostle for power in Asia," said Hugh White, a professor of strategic studies at the Australian National University
"It's all to do with how the Asian strategic order adapts to China's rising power and whether the United States can step back and give China more space. That's why it's so dangerous and so difficult."
When Tony Abbott met Japanese Prime Minister Shinzo Abe last month, eyebrows were raised when he warmly greeted his counterpart with the seemingly off-the-cuff remark that Japan was Australia's "best friend in Asia".
But the affectionate comment appears increasingly to be part of a deliberate strategic policy decision to reaffirm strategic alliances, rather than a gaffe that risked offending China.
Just weeks after sweeping to victory in September's federal election, the Coalition government struck a strategic three-way agreement with the US and Japan, which opposed "unilateral or coercive change in the status quo" in the East China Sea.
The same position was also put forward in a joint communique signed with the United States last week during the annual Australia-US ministerial consultations in Washington. It represented a clear departure from the previous year's stance to "not take a position on competing claims for sovereignty in the East China Sea".
"If I was the Chinese, I would read this as significantly more anti-China," White said.
But whether the fledgling government was swayed by Japan and the US into agreeing to a stronger position in the East China Sea, or agreed to it with eyes wide open, Australia's position is now committed.
"This is a bit like a slanging match in a playground, where you have to stick with your friends ... because of the need to demonstrate loyalty to them, rather than [having] any direct interest," said Kerry Brown, the executive director of Sydney University's China Studies Centre.
The question will be just what will be expected of Australia, now that it has pinned its colours to the mast, if an armed conflict does eventuate through a miscalculation or accident in the region. Still reeling from the damaging spying scandal that has soured relations with Jakarta, the fresh diplomatic spat already threatens to overshadow Julie Bishop's first visit to China as Foreign Minister.
And the government is already under pressure to honour a pre-election pledge to seal a much-vaunted free trade deal within a year.
But if Abbott has been caught off guard by the swift turn of events, he hasn't shown it.
Refusing to soften his stance, he rejected suggestions the diplomatic spat could jeopardise the country's most important trading relationship, insisting "China trades with us because it is in China's interest to trade with us".
"We are a strong ally of the United States, we are a strong ally of Japan, we have a very strong view that international disputes should be settled peacefully and in accordance with the rule of law and where we think that is not happening, or it is not happening appropriately, we will speak our mind," he said on Thursday.
Many analysts of the region remain guardedly optimistic that the US can accommodate China's rise without significant conflict but there is acceptance that periods of tension are inevitable.
But not everyone is so positive.
"Smooth relations between the United States and China will only be possible in the unlikely event that China adopts an extremely docile national security strategy, or in the equally unlikely event that the United States cedes its dominant position in the western Pacific," wrote international affairs experts Jennifer Lind and Daryl Press in The National Interest this year.
But China's neighbours are more suspicious of its intentions than ever.
China this year increased its defence budget by 10.7 per cent to $US119 billion ($130.6 billion) but some foreign experts estimate Beijing's real spending could be as high as $US200 billion.
"We see competition and conflict in the region deepening," South Korea's Foreign Minister, Yun Byung-se, said on Wednesday.
"Things can take a dramatic turn for the worse if territorial conflicts and historical issues are merged with nationalism."
Despite a stumbling economy, Japan has been forced to reverse a decade of declining military spending to contend with the increased tempo of Chinese military operations.
And there are suggestions China could claim another air defence zone, this time in the South China Sea, which would antagonise more of its neighbours, not least the Philippines and Vietnam.
Even as tensions frothed over the East China Sea this week, China's first aircraft carrier, the Liaoning, set off for training exercises in the politically sensitive waters further south.
"Whatever China does, it always attracts criticism. Let the critics go on, and we'll do what we do," said Zhu Feng, a professor of international relations at Peking University. "China is going through its rise - we just have too many jealous neighbours."