The US Navy has conducted another so-called Freedom of Navigation Operation (FONOP) in the South China Sea near the disputed Scarborough Shoal, provoking a protest from Chinese authorities. The maritime intrusion came ahead of a meeting of top naval commanders in New Delhi where US Admiral Harry Harris accused Beijing of being “a disruptive force in the Indo-Pacific.”

The USS Hopper, a guided missile destroyer, last Wednesday sailed within the 12-nautical mile territorial limit claimed by China around the shoal, which has been under Chinese control since 2012. The US, which has no territorial claims in the South China Sea, insists on the right to “freedom of navigation” and has continued its provocative operations, by air and sea, in the sensitive area despite Chinese opposition.

Chinese foreign ministry spokesman Lu Kang criticised the US actions, saying: “The Chinese navy carried out identification and verification procedures in accordance with the law and warned the US vessel to leave.” He declared that China was “strongly dissatisfied” and warned it would take “necessary measures to firmly safeguard its sovereignty.”

Washington has been steadily escalating its confrontation with China in the South China Sea. This began under the Obama administration, which seized on the issue as a means of driving a wedge between Beijing and its neighbours in South East Asia. The Trump administration, which is targeting China over trade and North Korea, is continuing to challenge China in the contested waters.

The USS Hopper’s intrusion is the first within the territorial limit around the Scarborough Shoal, an isolated islet strategically located some 200 kilometres west of the main Philippine island of Luzon. To date, China has not attempted to begin dredging and developing facilities on the shoal, as it has done on islets under its control in the Spratly and Paracel groups.

Philippine President Rodrigo Duterte, unlike his predecessor Benigno Aquino, has attempted to reduce tensions with China and improve economic ties. Chinese academic Zhang Jie told the South China Morning Post that the contested shoal was the unstated bottom line in its relations with China. “It has asked China not to build on the shoal, which China has not,” she said.

In response to the latest FONOP, Duterte’s presidential spokesman Harry Roque reiterated the Philippine claim over the Scarborough Shoal, then added: “We do not wish to be part of a US-China intramural [contest]. The United States can take care of its own interest.”

A US Navy spokeswoman claimed on Saturday that the USS Hopper’s intrusion was simply part of “routine and regular FONOPs as we have done in the past and will continue to do so in the future.” Defending the US actions, Lieutenant Commander Nicole Schwegman absurdly declared: “FONOPs are not about any one country, nor are they about making political statements.”

Both the timing of the naval provocation and the decision to target it against one of the most sensitive disputed areas were highly political. Last Thursday, the day after the USS Hopper operation, Admiral Harris, head of the US Pacific Command, met in New Delhi with top naval officers from India, Japan and Australia—the members of the so-called Quadrilateral or Quad.

Harris, who is known for an aggressive stance against China, declared: “I believe the reality is that China is a disruptive transitional force in the Indo-Pacific.” He blamed Beijing for the “trust deficit” in the region and urged other countries to join Washington’s actions against China. “We must be willing to take the tough decisions to ensure the Indo-Pacific region and Indian Ocean remain free, open and prosperous,” he said.

In reality, the US is recklessly risking a naval clash that could trigger open conflict as it seeks to maintain its dominance in the Indo-Pacific. The so-called Quad is a diplomatic initiative aimed at cementing closer military collaboration with US allies, Japan and Australia, and India, a US strategic partner. On the platform with Harris were the naval chiefs from India, Australia and Japan—respectively admirals Sunil Lanba, Tim Barrett and Katsutoshi Kawano.

Kawano said: “China’s military power is becoming more powerful and expanding. In the East and South China Seas, China has been ignoring international law.” He declared that the four countries must cooperate “in order to deter Chinese provocations.”

Lanba complained that China was developing port facilities in countries like Sri Lanka and Pakistan, giving it greater access to the Indian Ocean, which New Delhi has always regarded as its backyard.

Just hours before the forum began, India conducted its own show of military force, carrying out a fifth test of the Agni 5 ballistic missile, which has a range of 5,000 kilometres and is specifically targeted against China. Last year, the Indian and Chinese armies faced off in a dangerous confrontation in contested border areas.

In all but name, the Quad is a developing military alliance directed against China. Last year Japan joined India and the US in their Malabar joint naval war games, which the Pentagon is keen for Australia to join as well. Harris has also pressed other countries to join in the US FONOPs exercises in the South China Sea, but all have declined, thus far.

Washington’s aggressive stance against China in the South China Sea is underpinned by the recent release of the Pentagon’s National Defence Strategy. It identifies “long-term strategic competitions with China and Russia” as “the principal priorities” and calls for “increased and sustained investment, because of the magnitude of the threats they pose to US security and prosperity today, and the potential for those threats to increase in the future.”

The document nominates the South China Sea as an area where the US must take action. “China is a strategic competitor using predatory economics to intimidate its neighbours while militarising features in the South China Sea,” it states.

The danger of an incident in the South China Sea triggering a war was underscored just over a year ago when a US Navy aircraft and a Chinese surveillance plane came within 300 metres of each other near the Scarborough Shoal.