An F-15 fighter of the South Korean Air Force. Photo: AFP

SEOUL – South Korean fighters were scrambled to counter a joint intrusion by Chinese-Russian aircraft that probed one of the most sensitive points in the troubled Korean-Japanese-US defense posture in Northeast Asia.

The intrusion appears to represent an upgrade of Sino-Russian military cooperation, while probing a lack of defense coordination between Japan and South Korea.

Four Chinese and 15 Russian aircraft penetrated the Korean Air Defense Identification Zone, or KADIZ, on Tuesday, according to statements from the South Korean Joint Chiefs of Staff that were reported by local news sources.

“We believe that it was joint training by Chinese and Russian militaries,” a JCS spokesman said.

Four Chinese H-6 bombers entered the KADIZ from the west of the submerged reef of Ieo – whose ownership is disputed by China and Korea – which lies off the south of the peninsula at around 8 am. Two then flew eastward, near the island of Ulleungdo off Korea’s east coast, before exiting the zone.

The Chinese aircraft identified themselves before entering the KADIZ but 15 Russian planes – Tu-95 bombers, Su fighter jets and A-50 AWACS aircraft – entered the zone from the north without doing so.

The Russian flight path was close to the South Korean administered Dokdo Islets, equidistant in the Sea of Japan between the two countries. The islets are also claimed by Japan, which calls them Takeshima. The Russian aircraft continued to fly in and out of the eastern edge of the KADIZ until 3 pm.

It was the fourth such intrusion into the KADIZ by Chinese aircraft this year, and the first by Russia, a spokesperson at the South Korean Ministry of National Defense told Asia Times.

Air defense identification zones over Japan (blue), South Korea (green), China (pink), and Taiwan/ROC (Orange). Image: Wikimedia

While an ADIZ is not defined as sovereign air space, which covers land and extends 12 miles out to sea, under international law, the widely accepted protocol is that aircraft identify themselves before entering.

Complicating the matter in the area is that Chinese, South Korean and Japanese ADIZs all overlap south of the Korean peninsula. The overlapping ADIZs also cover areas disputed by China and South Korea (Ieo Reef) and by China and Japan (the Senkaku/Diaoyu islands).

Moreover, Russia does not recognize the South Korean ADIZ.

Unlike a similar incident in July 2019 when two Russian Tu-95s flew directly over Dokdo/Takeshima, the Korean aircraft did not fire warning shots on Tuesday. However, Seoul did lodge diplomatic protests with both China and Russia.

What was the aim?

The development suggests an emergent interaction between China and Russian forces in the region.

“It’s another incident where we see Chinese and Russian cooperation,” Chun In-bum, a retired South Korean general, told Asia Times. “In order to plan something like that they must have conducted detailed prior consultations and detailed planning at all levels.”

The aim of the probe was likely “to gain data and look at reaction times and see how we react,” he said.

The buzzing operations may be an emergent trend. “When it happened last time it was a first,” he said. “Now, it seems to be becoming a regular practice.”

While the intrusion may have been geared to test Russo-Chinese cooperation and communications, it may equally have been designed to probe the lack of cooperation between Korean and Japanese air-defense nets.

“There is, for sure, a high possibility that they are doing so,” Chun said.

Asia Times has been unable to discover whether direct communications link the Japanese and South Korean air forces. However, the lack of security cooperation between the two democratic neighbors has long irked the US, which has defense alliances with both countries but no regional, trilateral security architecture.

More strategically, the operation may be aimed at priyng Japan and South Korea apart. In the last intrusion, Tokyo made a formal complaint after the South Korean aircraft fired over Dokdo/Takeshima, causing Seoul to bristle.

“The Chinese do think about splitting alliances, so much of what they do is directed at that,”  Grant Newsham, a retired US Marine lieutenant colonel with wide experience in the region, told Asia Times. “If you can keep the Japanese and South Koreans at each others’ throats there is no downside, and it distracts the Americans.”

Though both countries maintain defense attaches in their respective embassies, the only official link between the Japanese and South Korean militaries is an intelligence-sharing agreement.

Even that slender thread was nearly severed in 2019 when Seoul, engaged in an emotive trade dispute with Tokyo, threatened to end the agreement. Seoul decided against the move in November of that year after likely US pressure.

Earlier, in October 2018, Seoul ordered a Japanese warship visiting a Korean naval review to lower its flag – which many Koreans consider symbolic of an imperialist past. The Japanese vessel opted not to join the review.

And in December 2018, a South Korean destroyer “painted” a Japanese reconnaissance aircraft with its target radar in an incident that caused a major diplomatic brouhaha. It remains unexplained and – at least publicly – unresolved to this day.

Given that there are US air bases in both Korea and Japan, the Sino-Russian signal could also have been aimed at the United States, Newsham said.

“It is definitely both [China and Russia] sending a message to immediate parties, but maybe even more so to the Americans with a new administration coming in, for which they have no respect at all,” he said. “This is muscle-flexing and maybe a shape of what’s to come.”

Looking at the region’s bigger picture, the US Navy has been patrolling in waters that are highly sensitive for Beijing: Off the island of Taiwan, which China claims, and in the South China Sea, where Beijing has built a string of military bases on reefs and islets whose ownerships are disputed with Southeast Asian states.

US ships are frequent visitors to South Korean and Japanese ports, and Washington maintains air bases in both countries. US aircraft based in Japan have conducted flights over the South China Sea.

A US Air Force B-1B Lancer bomber (R), US F-35B stealth jet fighters (bottom) and South Korean F-15K fighter jets (top) flying over South Korea in a joint exercise. Photo: South Korean Defense Ministry/AFP

Nameless alliances

For both sides, it is a tale of no alliances. No security pact links Japan and South Korea, but neither does one link China and Russia.

Even though two third-party sources told Asia Times that Seoul and Tokyo’s military establishments are on friendlier terms than their political establishments, defense cooperation between Seoul and Tokyo has suffered in the last two years.

Conversely, while there may be no formal alliance linking Beijing and Moscow, both militaries have been upgrading cooperation for well over a decade.

Since a ground-breaking joint training exercise in 2005, the Chinese and Russian armed forces have held a range of drills together in China, Central Asia and Russia under the banner of the Shanghai Cooperative Organization in China, Russia and Central Asia.

More notably, a Chinese brigade took part in the huge Vostok  (“East”) exercises in the Russian Far East in 2018 – seen as the biggest military drills held by any armed forces since the end of the Cold War.

A July 2020 paper, “Military Cooperation Between Russia and China: The Military Alliance Without an Agreement?” noted that cooperative drills have expanded to wider geographies, with naval units holding held joint exercises in the Black Sea, the Baltic and the Mediterranean, the Yellow Sea and the South China Sea.

According to the paper, which was published by the Estonia-based International Center for Defense and Security,  a Chinese guided-missile frigate and a Russian guided-missile cruiser held joint exercises with the South African navy in late 2019. Subsequently, Russia, China and Iran held joint naval exercises in the Indian Ocean and Sea of Oman.

Cooperation has also ramped up in education and air programs, the paper found.

By end-2016, more than 3,600 Chinese officers had been trained at Russian military academies, Russian Defense Minister Sergey Shogyu said. And Shoygu stated that joint air patrols by Russian and Chinese warplanes over the Sea of Japan represented two neighbors seeking strategic partnerships”.

“Russia and China are thus messaging to everyone that they want to ensure their security.”

This suggests an ongoing hardening of positions.

Russian and Chinese soldiers take aim in a 2018 joint military exercise. Image: Twitter

That is problematic for Japan and South Korea. Both share security partnerships and democratic governance systems with the United States. But both are economically reliant upon China – the top trade partner for each nation.

Even so, while Tuesday’s flights into the KADIZ may be part of a trend, they are not game-changers in themselves.

“I don’t think it is that serious. It’s a pretty low-cost way to sort of poke somebody,” said Newsham. “They are pushing at the edge of empires the way the Mongols and the Huns used to do.”

Chun, however, warned that Chinese and Russian aerial probes generate tensions.

“I have nothing against training, but the Chinese and Russians need to be very responsible,” he said. “By teasing us like this, they are creating an unwanted and unnecessary situation.”

And the moves could backfire by turning the attention of political communities in Seoul and Tokyo to a shared menace.

“This just proves that Korea and Japan are in the same boat,” Chun said. “All the [bilateral] bickering is not helping the wider challenge that both countries face.”