China's aircraft stole the headlines early in the week. But satellite photos reveal why they were in the skies – three allied aircraft carrier task groups operating in the South China Sea.
The People's Liberation air force (PLAF) dramatically upped the ante between Friday, October 1, and Monday, October 4, with 149 aircraft reportedly probing Taiwanese air space.
Chairman Xi Jinping's steadily escalating rhetoric against the island democracy of 24 million people was the most obvious link. But satellite photos and military statements indicate another cause.
Three aircraft carriers, two helicopter assault ships and some 20 escorting warships were active in the South China Sea.
The ships from the United States, United Kingdom, Australia, Japan, Canada, the Netherlands and New Zealand had come together to demonstrate international unity, and to practice complex, large-scale joint operations.
It was a powerful demonstration of the unified front the seven democracies presented China over its Himalayan, Taiwan, South and East China Seas stand-offs.
And, as with every other aircraft carrier visit to the South China Sea in the past year, Beijing felt compelled to escalate in response.
So it did so. In the air and at sea.
And just if there was any doubt, China's ambassador to Southeast Asia tweeted: ""By dispatching 149 warplanes near #Taiwan island since Oct 1, the #PLA sent strong warning to the Taiwan secessionists & their foreign supporters".
Australia's helicopter assault ship HMAS Canberra, the frigate HMAS Anzac and the support ship HMAS Sirius departed Manila late last week. It had been visiting as a show of support and to participate in drills with the Philippines armed forces.
The small task group joined the British destroyer HMS Diamond as it passed through the South China Sea to Singapore. As it did so, Beijing initiated the most intense period of air operations in the region since the 1949 civil war.
The Ministry of National Defence in Taipei reported 38 Peoples Liberation Army air force (PLAAF) aircraft active in its Air Defence Identification Zone (ADIZ).
It was the most significant incursion to date. But it would soon be overshadowed.
During the day, four groups comprising 25 aircraft, including four Su-30 heavy fighters, 18 J-16 fighters, two H-6 strategic bombers and a Y-8 surveillance aircraft crossed between mainland Taiwan and its Pratas Island outpost in the South China Sea.
Another 13 (10 J-16, two H-6 and a KJ-500 radar command aircraft) entered the Luzon Strait between Taiwan and the Philippines in the evening.
It's almost certain more Chinese aircraft were active over the South China Sea. But, if these did not enter Taiwan's early warning zone, their activity would not have been reported publicly.
The Australian warships were headed southwest, past the disputed Spratly Islands towards Singapore. HMAS Canberra docked there on Tuesday, October 5.
But, by then, tensions were only just coming off the boil in the South China Sea.
All weekend, the large-scale air operations continued. But, on Monday, October 4, Beijing sent a record 56 combat aircraft through Taiwan's ADIZ.
It was almost double the previous largest operation.
It was a clear show of strength.
The KJ-500 radar aircraft could track and target allied ships and planes over great distances. The H-6 bombers could use that information to target their long-range carrier-killer missiles. And the heavy fighters could keep any opposition at arm's length.
Beijing's pride was at stake.
HMS Queen Elizabeth was in the South China Sea, west of the Luzon Strait separating Taiwan and the Philippines. The USS Carl Vinson battle group was nearby, just north of the disputed Scarborough Shoal. On the other side of the strait was the aircraft carrier USS Ronald Reagan and the Japanese helicopter assault ship JS Ise, along with their escorts.
The force had just separated after travelling along the east of Taiwan after an exercise off Japan's Okinawa island.
They were being watched.
Analysis of satellite imagery revealed the operations of HMS Queen Elizabeth and USS Carl Vinson battle groups. But around them were unidentified warships – almost certainly vessels of the People's Liberation Army navy (PLAN).
And the tracks of PLAAF aircraft flights published by Taiwan reveal they had been probing the Luzon Strait and the northern South China Sea.
Taiwanese officials stated that it appeared China had conducted a mock air attack on the combined allied fleet. They expressed concern at the escalation: "This is approaching the brink of conflict," one official told local media.
"In my opinion, the surge of military aircraft may signify how much Beijing had been irritated over the recent gathering of US and UK carrier strike groups near Taiwan," comments Ho Chi Minh-based naval analyst Duan Dang. "Such a response would be anticipated from the PRC every time a US aircraft carrier transiting Bashi Channel (Luzon Strait)".
It has been a pattern in recent months. Each time a US carrier battle group has entered the South China Sea, Taiwan has recorded a dramatic spike in Chinese air activity within its "buffer" zone.
It's also one of the reasons for the combined nations' show of strength.
"This training, which brings together three Carrier Strike Groups, embodies the strong will of the participating countries to realise a Free and Open Indo-Pacific," said Japan's commander Rear Admiral Konno Yasushige. "The JMSDF will work closely with allied and friendly navies, which share the same objectives, to respond to global challenges and defend maritime order based on the rule of law."
British Commodore Steve Moorhouse added that the British CSG "offers the largest 5th Generation air wing afloat today and working with our close allies to develop operating procedures and capabilities while concurrently showcasing the agility of land and carrier-based aviation in the Indo-Pacific demonstrates our commitment to the region."
Xi orders escalation
Earlier this week, Chairman Xi reportedly told his Central Military Commission to "increase military pressure" on southern Taiwan and demonstrate that China was "always ready to fight".
Beijing also rejected Washington's Sunday expression of "concern" over military activity near Taiwan.
"The US statement sent a very wrong and irresponsible signal, and China will take all measures necessary to crush any Taiwan independence attempts", the Chinese Foreign Ministry said on Monday as its 56 combat aircraft were in the air.
"Taiwan independence is doomed to fail," insisted ministry spokesman Hua Chunying.
"The PLA's continued drills showed that China has the total control over the region, and sent a powerful warning to the secessionists and their foreign supporters," the Chinese Communist Party-controlled Global Times news service added.
"More PLA aircraft and vessels will train near the island, increasing preparedness to carry out missions to safeguard national sovereignty and territorial integrity should it become necessary," it quoted a Beijing-based military expert as saying.
As the drama unfolded in the skies and on the waters of the South China Sea, former Trump National Security Adviser and retired Army General HR McMaster told a Hudson Institute think-tank gathering that he felt the world was entering a "very dangerous time".
"I think that we're in a race — we being Taiwan and the United States but also Japan … and others in the region including our allies, Australia and so forth — to ensure deterrence by denial. To convince the Chinese Communist Party leadership and the People's Liberation Army that they can't accomplish their objectives through the use of force or coercion vis a vis Taiwan."