The US Navy is now reportedly planning to sail right into the 12nautical mile zone that defines territorial limits around one of the major points of dispute, the Spratly Islands, defying the Chinese claim and asserting freedom of navigation for international vessels. Beijing has warned that this would be a "grave mistake for the United States to use military means to challenge China". The official Xinhua newsagency said last week that "China has every right to defend its rights and strategic interests, and will respond to any provocation appropriately and decisively". Beijing would have no option but to build up its defences on the islands, Xinhua said. Indeed, an unnamed Chinese military official told Newsweek magazine: "There are 209 land features still unoccupied in the South China Sea and we could seize them all ... and we could build on them in 18 months." China is very consciously implementing a new national strategy of assertiveness towards the rest of the world. The late paramount leader Deng Xiaoping set out the national stance in the 1990s as one of "hide your brightness, bide your time". It was a philosophy of restraint to allow China to concentrate on an economic and military build-up. But China's current president, Xi Jinping, has decided that is time to show China's brightness and no longer bide its time. In October 2013, he convened the highest level meeting on foreign policy since the People's Republic of China was founded in 1949, according to a leading Chinese scholar, Yan Xuetong.

At that meeting, he promulgated a new national strategy – "strive for achievement" as China seeks national restoration as the greatest power in Asia. But what Xi calls striving for achievement, other countries consider to be coercive diplomacy. Barack Obama in June described it as "throwing elbows and pushing people out of the way". Beijing ignored him. China's assertiveness was vindicated when the US did nothing in response. China had achieved what traditional strategy considers the ultimate in warfare: "Defeating the enemy without ever fighting," as Sun Tzu's The Art of War puts it. But now, after protracted internal American government debate, US media report that the US Navy is on the brink of acting, and the region awaits. The US, like Australia, takes no side in the territorial dispute but insists that it not be settled forcibly. Ministers from Australia and the US discussed this issue at length in the annual AUSMIN consultations last week. Julie Bishop told the media that Washington and Canberra were "on the same page" on the matter of freedom of navigation.

But, contrary to some media reports, participants tell me that the US proposed no specific measures and Australia agreed to take no specific measures of its own. To now, the US has not decided precisely what it will do. To sail into the 12 nautical mile territorial claim is something that the US Navy has never done. To do it now would be seen to be provocative, and aimed squarely at Beijing. Yan, who is a sometime adviser to the government in Beijing, says that "the competition for power is a zero sum game and structural conflicts between the rising power and the existing power are inevitable. In a telling phrase, he adds: "When the strategy of annexation is not available, the competition will turn to how to make more allies." For now, Beijing seems to consider annexation to be very available. But the US and China are not the only great powers with a deep national interest in the question of who controls the world's busiest shipping route and the Asia's central maritime hub. At the weekend, Japan and India joined the US in naval exercises centred on hunting and killing submarines. It was important to have "naval partners who are like-minded friends and allies" said a Pentagon official, Amy Searight.

The Chinese worry deeply that there is an incipient alignment of these three great powers against China. Of course, this is something that Beijing can influence by its behaviour. They will align against China if they see it as necessary to manage Chinese aggression. The three big questions remain to be answered in the days ahead. Does the US have the strength of will to uphold the international order? Just how aggressive is the new China going to be? And which country should we be aligning ourselves with now? Peter Hartcher is international editor. Correction: An earlier version of this story was amended to attribute the quote of an unnamed Chinese military official to Newsweek magazine.