The ruling delivered overnight by the International Tribunal on the Law of the Sea under the Permanent Court of Arbitration in The Hague is one that will deeply discomfort Beijing. Since the Philippines put its case to the Tribunal in June 2013 China refused to participate in the Tribunal’s proceedings. Beijing stridently maintains that the Tribunal has no legitimate authority to make judgements about sovereignty claims in the South China Sea. Indeed the Court’s ‘Award’—as its judgement is called—makes no ruling about whether China or the Philippines has legitimate claims to any land features in the South China Sea.

But the ruling delivers a shattering blow to the legitimacy of Chinese claims over maritime area. It says that China’s claims of sovereignty within the ‘nine-dash line’ has no legitimacy and is harshly critical of Chinese environmental destruction of reefs and marine life.

The Tribunal’s media statement accompanying the Award uses remarkably strong language to set out its key findings. These include:

•       ‘The Tribunal concluded that there was no legal basis for China to claim historic rights to resources within the sea areas falling within the ‘nine-dash line’.’
•       ‘… the Tribunal concluded that none of the Spratly Islands is capable of generating extended maritime zones. … Having found that none of the features claimed by China was capable of generating an exclusive economic zone, the Tribunal found that it could—without delimiting a boundary—declare that certain sea areas are within the exclusive economic zone of the Philippines, because those areas are not overlapped by any possible entitlement of China.
•       ‘Having found that certain areas are within the exclusive economic zone of the Philippines, the Tribunal found that China had violated the Philippines’ sovereign rights in its exclusive economic zone …’
•       ‘[The Tribunal] found that China had caused severe harm to the coral reef environment and violated its obligation to preserve and protect fragile ecosystems and the habitat of depleted, threatened, or endangered species.’
•       ‘The Tribunal found, … that China’s recent large-scale land reclamation and construction of artificial islands was incompatible with the obligations on a State during dispute resolution proceedings, insofar as China has inflicted irreparable harm to the marine environment, built a large artificial island in the Philippines’ exclusive economic zone, and destroyed evidence of the natural condition of features in the South China Sea that formed part of the Parties’ dispute.

There’s much more along those harsh lines and collectively the judgement amounts to the most comprehensive condemnation of China’s threadbare sovereignty claims.

So what happens now? China appears to be locked on to a path of ever more stridently asserting its claim to the vast bulk of the South China Sea. In addition to the island construction, runway building and stationing of radars, combat aircraft and surface-to-air missiles on those islands, Beijing has recently conducted large scale naval exercises which included extensive missile and torpedo launches.

The island building and exercises have featured prominently in Chinese domestic media reporting which is building nationalistic ardour about China’s claims. President Xi’s domestic credibility, not least his ability to keep control of the People’s Liberation Army, is now in some part hostage to China continuing to assert its unilateral claim to everything falling within the nine-dash line.

Beijing has also worked hard, and largely successfully, to break ASEAN’s always faltering unity on the South China Sea. There’s clearly an attempt underway to see if the Philippines’ new president, Rodrigo Duterte, can be induced to negotiate over Manila’s claims in the Spratly Islands in return for economic assistance. A collection of motley African kleptocracies have been persuaded to spruik the legitimacy of Chinese claims, although it’s doubtful that Zimbabwe—a land-locked dictatorship—has much that’s useful to say about the Law of the Sea.

Other countries, Australia included, have been warned by China not to get too vocal in pushing the case for a resolution to sovereignty disputes in the South China Sea based on what the Australian 2016 Defence White Paper repeatedly calls a ‘rules based global order.’ Canberra recently received a pat on the head from Mr Xiangmo Huang, Chairman of the Australia­–China Relations Institute at the University of Technology in Sydney, saying it was ‘wise to resist the subtle American pressure to join its patrols in the South China Sea.’ Better to be cautious, he observed in the Australian Financial Review, than to make ‘any knee-jerk reactions Australia may end up regretting.’

But it’s not clear just how long our sotto voce approach will suffice. The Tribunal ruling makes it painfully clear that there’s a stark incompatibility between Australia and China’s approach. Readers will recall the 2016 Defence White Paper claims that Australia’s ‘… second Strategic Defence Interest is in a secure nearer region, encompassing maritime South East Asia and the South Pacific.’ In other words, we assert a critical national security interest in the security of a region now almost entirely claimed by China. Don’t forget we are spending $89 billion re-building the Navy to contribute to regional maritime security. These submarines and frigates won’t be sailing off Antarctica.

As is so often the case, Washington’s policy approach will critically define what happens next. The Obama administration has slowly and reluctantly come around to the realisation that disputes over a bunch of rocks in the South China Sea really do have the potential to damage the broader US–China relationship. Even though the US has never become a party to the Law of the Sea Convention it’s impossible that Washington won’t respond to a judgement from the Permanent Court of Arbitration which finds so strongly against China’s actions in the South China Sea.

We should expect that the US will conduct more Freedom of Navigation and overflight manoeuvres in the region. We should also expect that the US will turn to its key regional allies to do the same. A phone call from the White House won’t be far away.