On Tuesday July 23, a rare face-off involving warplanes from Russia, China, South Korea, and Japan occurred in the East Asia waters near the disputed island Liancourt Rock (known as Dokdo to South Korea and Takeshima to Japanese).

South Korea fired hundreds of warning shots at Russian A-50 aircraft and bombers on Tuesday morning, following an accusation from the East Asian nation that Russia had intruded into South Korean airspace, South Korean’s Joint Chief of Staff stated.

“This is the first time Russian military aircraft have invaded our airspace,” an official from the Joint Chiefs of Staff was quoted saying by Newsweek.

Russia confirmed the joint air drill with China

Tensions ran high after Japan and South Korea claimed that they witnessed two Chinese-6 bombers with the Russian fighter jets in the incident.

South Korean news agency Yonhap reported that the country’s military was upset by the presence of four Russian and Chinese jets in the Koreans’ Air Defense Identification Zone (KADIZ) set up by South Korea in 1950 and was later adjusted in 2013.

An ADIZ is an airspace surrounding a country or part of it where the identification, control, and location of the civil plane is carried out in the interest of national security. Overseas military aircraft must provide details of their destinations and routes before entering the zone.

However, ADIZ is not regulated under international law, meaning that other countries claims can be refuted or overlap. In this case, South Korea, Japan, Russia, and China have overlapping claims over the ADIZs.

On Tuesday evening, Russian’s Defense Ministry confirmed that its fire jets were holding a joint patrol with Chinese aircraft, aimed at strengthening Russia-China ties, not targeting the third party.

“The joint patrol was carried out with the aim of deepening Russian-Chinese relations within our all-encompassing partnership, of further increasing cooperation between our armed forces, and of perfecting their capabilities to carry out joint actions, and of strengthening global strategic security,” the ministry’s statement said.

Prior to the statement, the ministry denied Seoul’s allegation on airspace intrusion and accused a South Korean pilot of flying dangerously.

“We have seen statements in the South Korean media quoting words allegedly said by our acting military attaché,” a spokesman for Russia’s embassy in South Korea said, as Interfax news agency reported.

One day after the air spat, Seoul said that a Russian’s government official admitted that Moscow had illegally intruded into the KADIZ, arguing that such an act was unintended. Moscow also promised to carry out an immediate investigation into that case, where the official claimed that a technical glitch was behind the incident.

Japan’s and US responses

Tokyo filed a legal complaint against both Seoul and Moscow for an alleged airspace violation, adding that South Korea’s reaction was unacceptable.

“In light of Japan’s stance regarding sovereignty over Takeshima, the South Korean military aircraft’s having carried out warning shots is totally unacceptable and extremely regrettable.” Japanese Chief Cabinet Secretary Yoshihide Suga stated as The Korea Herald wrote

Takeshima (Bamboo Island), or Dokdo (Solitary Island) to South Koreans, has been a thorn in the Japan-South Korea relationship, given the island’s vast sea resources and natural gas. South Korea has occupied this island since 1954.

Both East Asian nations have been involved in a trade war, triggered by Seoul’s complaint over compensation from Tokyo for the World War II’ comfort women”. Japan then retaliated by imposing an export restriction for semi-conductor’s export to South Korea.

Meanwhile, the US Department of Defense expressed support for Japan and South Korea after the alleged airspace invasion by Russian and Chinese fighter jets.

“The United States strongly supports our ROK and Japanese allies and their responses to airspace incursions by Chinese and Russian aircraft,” Pentagon spokesman Lt. Col. Dave Eastburn said in response to a query from Yonhap News Agency, adding that the Pentagon would coordinate with South Korea and Japan to monitor the activities.

Russia-China military alliance still an unlikely option

The joint bomber jet patrols between Russia and China have shown the growing capabilities of both countries’ militaries. Moscow has just shipped the second batch of the S-400 anti-missile defense system to China, a Russian government source said, according to The Diplomat.

China’s national defense white paper also highlights military cooperation with Russia, stating that “the military relationship between China and Russia continues to develop at a high level, enriching the China-Russia comprehensive strategic partnership of coordination for a new era and playing a significant role in maintaining global strategic stability.”

However, despite their stronger military ties, both countries are not allies, meaning that they are not commited to protecting each other in the event of war (since there is no formal pact that makes them do so), and may see each other as a threat.

Russia and China may unite against the US hegemony. However, both have a bitter history. China and Russia share the same ambitions to be the world’s greatest military powers, making them only want to form “a strategic partnership,” not “alliance.”