Simultaneous Deployment of Chinese and Russian Navies in the Tsushima Strait: Structural Transformation of Maritime Security in Northeast Asia (May 2026)

In early May 2026, a large-scale deployment of naval vessels by the Chinese Navy and the Russian Navy was confirmed in the Tsushima Strait, Japan. According to a statement from the Ministry of Defense and the Joint Staff Office, three missile destroyers of the Chinese Navy passed through the Tsushima Strait heading towards the East China Sea from May 1 to 2, and a total of ten vessels, including four ships and six cargo ships from the Russian Navy, advanced southwest through the same strait into the East China Sea from May 9 to 10. These two events are not coincidental occurrences. They indicate a structural change in which the maritime strategies of China and Russia are intersecting at the Tsushima Strait, the most critical chokepoint in Northeast Asia.

The movements of the Chinese Navy are particularly noteworthy. Around 11 PM on May 1, three vessels were confirmed in waters approximately 60 km northeast of Tsushima, Nagasaki Prefecture: the Luyang III-class missile destroyers "Guiyang" and "Chengdu," and the Renhai-class missile destroyer "Lhasa." Analyzing the behavior patterns of these vessels reveals deeper operational intentions. "Guiyang" and "Lhasa" entered the Sea of Japan from the East China Sea between March 30 and 31 and are believed to have been deployed in the Sea of Japan for about a month. In contrast, "Chengdu" exhibited unusual behavior by repeatedly entering and exiting the Sea of Japan shortly after its entry on March 30-31, sailing through the Tsushima Strait on two consecutive days, April 27 and 28. Such high-frequency and repetitive passages through the Tsushima Strait suggest that the Chinese Navy is increasingly utilizing the Sea of Japan as an operational area. The fact that the Chinese Navy, which focused on coastal defense until the 1980s, has normalized its presence in the Sea of Japan in just 40 years is nothing short of a tectonic shift in the maritime power balance in Northeast Asia.

Qualitative changes in equipment are also significant. "Lhasa" is one of the Renhai-class (Type 055) missile destroyers, with a standard displacement of approximately 11,000 tons and equipped with a 112-cell vertical launch system. This surpasses the scale of the U.S. Navy's Arleigh Burke-class Flight IIA (standard displacement of about 9,500 tons, 96 cells) and the Japan Maritime Self-Defense Force's Maya-class destroyers (standard displacement of about 8,200 tons, 96 cells), making it the largest surface combatant in the Chinese Navy. The Renhai-class is a multi-purpose platform that integrates powerful anti-air, anti-ship, anti-submarine, and land attack capabilities into a single vessel, and it is expected to be equipped with hypersonic missiles in the future. Additionally, the Luyang III-class (Type 052D), known as the "Chinese Aegis," is the main destroyer of the Chinese Navy, with over 25 vessels currently in service. The long-term deployment of these vessels in the Sea of Japan is evidence that the Chinese Navy's blue-water operational capabilities are steadily maturing.

The simultaneous passage of the Russian Navy's ten-vessel convoy through the Tsushima Strait also illustrates the complexity of the maritime security environment in Northeast Asia from a different angle. This convoy consisted of the Steregushchiy-class corvettes "Sovershennyy" and "Rezky," a Dubna-class supply ship, the ocean tug "Andrei Stepanov," and six cargo ships (Maia 1, Lady D, Lady Mariia, Lady R, MV Kapitan Danilkin, among others). Some of these cargo ships have been sanctioned by the U.S., EU, and South Korea for their involvement in Russia's "shadow fleet." While this navigation falls within the scope of international navigation rights in the Tsushima Strait, the escort by combat ships of the Pacific Fleet indicates that Russia is incorporating commercial shipping under naval protection to evade sanctions. Since early 2026, Russia has been conducting similar escort operations in the Baltic Sea and the Mediterranean, and the passage through the Tsushima Strait signifies that this operational model has expanded to the Indo-Pacific region.

Japan's response is also noteworthy. The missile boat "Ootaka," belonging to the 3rd Patrol Corps of the Japan Maritime Self-Defense Force, conducted surveillance and information gathering against the Chinese vessels, while the missile boat "Shirataka" and the P-1 patrol aircraft monitored the Russian convoy. The rapid public disclosure of both incidents with images by the Joint Staff Office reflects Japan's emphasis on ensuring transparency regarding military activities around the Tsushima Strait and establishing information superiority.

An essential factor in interpreting these movements is the rapid transformation of Japan's defense posture. The defense budget for fiscal year 2026, approved by the Cabinet in December 2025, has reached a record high of 9.4 trillion yen (approximately $58 billion), focusing on the introduction of Tomahawk cruise missiles (with a range of over 1,600 km), the establishment of a multi-layered defense system using unmanned systems, the joint development of next-generation fighter jets with the UK and Italy (targeting deployment by 2035, with development costs exceeding 160 billion yen), and the deployment of surface-to-air missiles to the southwestern islands. The deployment of medium-range surface-to-air missiles (Type 03) to Yonaguni Island (approximately 110 km from Taiwan) has already begun, and a defense network along the first island chain, including Ishigaki and Miyako Islands, is being formed. In March 2025, the Joint Operations Command was also established, creating a system for the integrated operation of the Ground, Maritime, and Air Self-Defense Forces, as well as space and cyber domains, from peacetime.

On the other hand, North Korea's missile development has also escalated qualitatively and quantitatively in 2026. Following the April tests of ballistic missiles equipped with cluster warheads and multiple short-range ballistic missile launches on April 19, improvements to solid-fuel rocket motors are ongoing, and there are analyses suggesting that the development of the multiple warhead-capable ICBM "Hwasong-20" is accelerating. A new "Five-Year Military Development Plan (2026-2030)" has begun in 2026, and it is expected that the enhancement of nuclear capabilities and the asymmetric strengthening of conventional forces will be pursued simultaneously.

The simultaneous deployment of the Chinese and Russian navies in the Tsushima Strait in early May is not merely a coincidence of timing. The Tsushima Strait, a narrow passage approximately 100 km wide connecting the Sea of Japan and the East China Sea, is geopolitically a chokepoint that can be described as the "gate of the maritime corridor" in Northeast Asia. The situation where China's blue-water navy and Russia's shadow fleet with escorts intersect here poses new challenges to the existing maritime security framework centered around the Japan-U.S. alliance. In other words, we are entering an era of complex maritime hybrid warfare, where traditional military threats and hybrid non-military means (sanction-evading convoys, militia-like mobilization of fishing boats, and the gray zone utilization of maritime law) are being deployed simultaneously. Japan's direction of "stand-off defense" and "unmanned and multi-layered" as outlined in the fiscal year 2026 defense budget should be understood as a strategic response to this new threat environment.