A Chinese fighter confronts a US Navy plane with CNN equipment on board

Kadena Air Base, Japan (CNN) – The US Navy reconnaissance plane is flying at 6,553 meters (21,500 feet) over the South China Sea, 30 miles from the disputed Paracel Islands, a group of about 130 tiny atolls, the largest of which are home to Chinese military bases.

Hear voice, purportedly from a Chinese People’s Liberation Army airfield, over the radio of a US Navy P-8 Poseidon as a CNN crew, with an infrequent arrival on the US flight.

“American plane: Chinese airspace is 12 nautical miles away,” he says. “Don’t get any closer or you will bear full responsibility.”

Within minutes, a Chinese fighter carrying air-to-air missiles intercepted the American plane, and it landed just 150 meters off its left wing.

The Chinese fighter was so close that the CNN team could see the pilots turning their heads to look at them, and could make out the red star on the tail fins and the missiles it was armed with.

Lt. Nicky Slaughter, pilot of the USS, salutes the two-seat, twin-engine People’s Liberation Army plane.

“PLA fighter, this is a US Navy P-8A. I raise them from the left wing and intend to advance west. I ask you to do the same, more.”

There was no response from the Chinese fighter, which escorted the American plane for 15 minutes before turning back.

For the CNN crew aboard the US flight, this is stark evidence of the tensions brewing in the South China Sea and between the US and China.

The commander of this US Navy mission has a different opinion.

“I would say it’s another Friday afternoon in the South China Sea,” Navy Commander Mark Hines told the CNN team.

potential trigger

In recent years, the South China Sea has become a major potential hotspot in the Asia-Pacific region. And its component islands, such as the Paracels, near which a US Navy plane was intercepted on Friday, are the subject of partially overlapping territorial claims by China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan.

Not only is the strategic waterway home to vast fish, oil and gas resources, but about a third of the world’s shipments pass through it, worth about $3.4 trillion in 2016, according to the China Energy Project. From the Center for Strategy and International. Studies (CSIS).

China claims historic jurisdiction over nearly the entire vast sea, and since 2014 has built small coral reefs and shoals on artificial islands heavily fortified with missiles, landing strips and weapons systems, prompting protests from other claimants.

The Paracels Islands, which China calls Xisha, lie in the north of the South China Sea, east of Da Nang, Vietnam, and south of China’s Hainan Island.

Named by Portuguese cartographers in the 16th century, they have no indigenous people, only Chinese military garrisons numbering 1,400, according to the CIA Factbook.

Around it are 12 nautical miles of airspace that China declared on Friday as its own, a claim Washington does not recognize.

The Spratly Island chain is located in the extreme southeast, just 300 kilometers from the Philippine island of Palawan.

In 2016, in a case brought by the Philippines, an international tribunal in The Hague to rule China’s claim to historical rights to most of the sea lacks legal basis.

But Beijing rejected the court’s ruling and continued its military expansion by building bases in the Spratly Islands, which it calls the Nansha Islands.

China also conducts regular military exercises in much of the South China Sea and maintains a large coast guard and fishing vessel presence in the disputed waters, which has often raised tensions with its neighbours.

On Friday, while flying close to the Philippines, the US Navy sighted a guided missile destroyer belonging to the People’s Liberation Army of China and swooped down about 1,000 feet to get a closer look, prompting more warnings from the People’s Liberation Army.

“American planes. American plane. This is the 173rd Chinese Navy warship. It’s approaching from low altitude. Indicate your intention,” the American plane’s radio heard.

The PLA’s 173rd warship, the destroyer Changsha, is probably armed with dozens of surface-to-air missiles.

Its pilot, 1st Lt. Slaughter, said the American aircraft would be kept at a safe distance.

The Chinese ship says: “American planes. American planes. This is a Chinese Navy warship 173. You are clearly endangering my safety. You are clearly endangering my safety.”

Slaughter replies, “I am a U.S. military aircraft. I will keep a safe distance from your unit,” and the American mission continues.

The US Navy claims these missions are routine.

According to the Pentagon, US ships and aircraft regularly operate wherever international law allows. But China claims that it is the US presence in the South China Sea that is fueling tensions.

When a US guided-missile cruiser sailed near the Spratly Islands in November, the People’s Liberation Army claimed that the action “seriously violated China’s sovereignty and security” and was “convincing evidence that the United States seeks maritime hegemony” and militarizes the South. China Sea.

The US Navy said the US ship carried out the operation “in accordance with international law and thereafter continued to conduct its normal operations in the free waters on the high seas”.

For Heinz, the US mission commander on Friday, tensions always lessen when he talks with the Chinese side.

He says silence brings uncertainty.

“When there is no answer, questions arise. Do they understand what we are saying? Do they understand our intentions? Do they understand that we mean no harm?”

For the most part, on Friday there have been responses. Hines says the meetings were “professional”. And he wants to keep it that way.

CNN’s Nectar Gan and Brad Lyndon contributed to this report.