US Defense Secretary Jim Mattis has spoken out ^[1] against China’s strategy of ‘intimidation and coercion’ in the South China Sea, including the deployment of anti-ship missiles, surface-to-air missiles and electronic jammers, and, more recently, the landing of nuclear-capable bomber aircraft at Woody Island. There are, Mattis warned, ‘consequences to China ignoring the international community’.

But what consequences? Two successive US administrations—Barack Obama’s and now Donald Trump’s—have failed to push back credibly against China’s expansionism in the South China Sea, which has accelerated despite a 2016 international arbitral tribunal ruling ^[2] invalidating its territorial claims there. Instead, the US has relied on rhetoric or symbolic actions.

For example, the United States has disinvited China from this summer’s 26‑country Rim of the Pacific (RIMPAC) naval exercise. The move has been played up as a potential indication that the US may finally be adopting a tougher approach towards China. Mattis himself has called the decision an ‘initial response’ to China’s militarisation of the South China Sea, which is twice the size of the Gulf of Mexico and 50% bigger than the Mediterranean Sea.

Similarly, the US Navy’s freedom of navigation (FON) operations ^[3], which are occurring more regularly under Trump than they did under Obama, have been widely hyped. After the most recent operation, in which a guided-missile cruiser and a destroyer sailed past the disputed Paracel Islands, Mattis declared that the US was the ‘only country ^[4]’ to stand up to China.

But China, too, has used America’s FON operations to play to the Chinese public, claiming ^[5] after the latest operation that its navy had ‘warned and expelled’ two US warships. More important, neither FON operations nor China’s exclusion from the RIMPAC exercise addresses the shifts in regional dynamics brought about by China’s island-building and militarisation, not to mention its bullying of its neighbours. As a result, they will not credibly deter China or reassure US allies.

The reality is that China’s incremental encroachments have collectively changed the facts in the South China Sea. It has consolidated its control over the strategic corridor between the Indian and Pacific Oceans, through which one‑third of global maritime trade—worth $5.3 trillion last year—passes. It is also asserting control over the region’s natural resources, by bullying and coercing other claimants seeking to explore for oil and gas in territories that they themselves control under the United Nations Convention on the Law of the Sea. Vietnam, for example, has been forced to scrap a project ^[6] on its own continental shelf.

Perhaps most ominous, China’s development of forward operating bases on man‑made South China Sea islands ‘appears complete ^[7]’, as Admiral Philip Davidson told a Senate committee in April before taking over the US Indo-Pacific Command. ‘China is now capable of controlling the South China Sea in all scenarios short of war with the US,’ Davidson confirmed.

Davidson’s characterisation is revealing. As China takes a long-term strategic approach to strengthening its hold over the South China Sea (and, increasingly, beyond), the US is focused solely on the prospect of all‑out war.

The Pentagon has flaunted its capability to demolish China’s artificial islands, whose creation Chinese President Xi Jinping has cited as one of his key accomplishments ^[8]. ‘I would just tell you,’ joint staff director Lt. Gen. Kenneth McKenzie recently said, ‘the US military has had a lot of experience in the western Pacific taking down small islands.’

If open war is China’s only vulnerability in the South China Sea, the US will lose the larger strategic competition. While seeking to protect its military freedom of navigation in the South China Sea, the US has turned a blind eye to China’s stealthy but aggressive assault ^[9] on the freedom of the seas, including restricting the rights of other countries in the region.

The only viable option is a credible strategy that pushes back against China’s use of coercion to advance its territorial and maritime revisionism. As Admiral Harry Harris cautioned ^[10] last month while departing as head of the US Indo-Pacific Command, ‘Without focused involvement and engagement by the US and our allies and partners, China will realise its dream of hegemony in Asia.’

Simply put, China is winning the battle for the South China Sea without firing a shot—or paying any international costs. While Trump is sustaining this trend, it began under Obama, on whose watch China created seven artificial islands and started militarising them.

Obama’s silence in 2012 when China occupied the disputed Scarborough Shoal—a traditional Philippine fishing ground located within that country’s exclusive economic zone—emboldened China to embark on a broader island-building strategy in the South China Sea the following year. By the time the US realised the scope and scale of China’s land-reclamation program, Russia grabbed its attention by annexing Crimea. Yet the long-term strategic implications of what China has achieved in the South China Sea are far more serious.

Unfortunately, when it comes to constraining China’s expansionism, Trump seems just as clueless as his predecessor. Focused obsessively on three issues—trade, North Korea and Iran—Trump has watched quietly as China builds up its military assets through frenzied construction ^[11] of permanent facilities on newly reclaimed land. And now China has begun making strategic inroads in the Indian Ocean and the East China Sea, threatening the interests of more countries, from India to Japan.

The South China Sea has been and will remain central to the contest for influence in the larger Indo-Pacific region. Thanks to US fecklessness, the widely shared vision of a free, open and democratic-led Indo-Pacific could give way to an illiberal, repressive regional order, with China in full control.