Russia’s Intensified Maritime and Aerial Intelligence Activities Around Japan

Since the start of Russia’s full-scale invasion of Ukraine in 2022, its military activities near Japan have notably intensified. Before the Ukraine war, Russian intelligence efforts around Japan were predominantly limited to air operations. Reconnaissance missions were conducted using aircraft such as the Tu-95 strategic bomber, IL-20 intelligence collection plane, Tu-142 maritime patrol aircraft, A-50 airborne early warning aircraft, IL-38 maritime patrol aircraft, and the Su-24 tactical reconnaissance aircraft.

However, maritime intelligence gathering, particularly using intelligence-gathering vessels (AGIs), was rare. An exception occurred in 2008 when a Russian Balzam-class AGI drifted near Okinawa. After that, no similar maritime activity was noted until March 20, 2022—one month into the Ukraine war—when a Vishnya-class AGI was detected near Tsushima Strait.

Since that point, Russia has steadily increased its naval intelligence presence around Japan, marking a significant strategic shift.

Timeline of Russian Naval Intelligence Activity

Key observations include:

• March 2022: First sighting of a Russian AGI near Tsushima in over a decade.
• July 2022: Russian AGI completed a full circumnavigation of Japan.
• October 2022: Vessel advanced into the Tsugaru Strait.
• March 2023: Another full circumnavigation around Japan.
• September 2023: Movement recorded from Misawa (northern Honshu) to Kanto, then Kyushu’s eastern coast, then back to Misawa and through the Soya Strait.
• March 2024: Activity from the Sea of Japan to the Sakishima Islands.
• August 2024: Movements similar to those in March.
• November 2024 to February 2025: AGI operated between the Sea of Japan, the Miyako Strait, and eastern Kyushu.
• February–March 2025: Repeated round-trips between the Sea of Japan and the Miyako Strait.

The Defense Ministry’s Joint Staff Office visually documented these unusual operations, highlighting their increased frequency and persistence.

Characteristics of Russian Intelligence Vessels

Two classes of vessels are mainly involved:

• Vishnya-class AGI (notable for large radomes and numerous antennas)
• Balzam-class AGI (smaller radomes)

Both are capable of intercepting communications between U.S. military bases in Japan and the U.S. mainland, as well as gathering radar electronic intelligence (ELINT) and communication intelligence (COMINT).

Interestingly, the larger radome-equipped vessels, such as the Vishnya-class, exhibited significant external rusting. This indicates that they had been mothballed or otherwise underused for an extended period and were hastily reactivated without time for repainting—suggesting a high level of urgency from the Russian side.

Each ship carries approximately 150 personnel and is equipped like a small to mid-sized land-based intelligence station. Stationing such a vessel close to Japanese territory for prolonged periods enables collection of higher-quality, more sensitive electronic intelligence compared to gathering data from distant continental stations.

Strategic Motivations Behind Russia’s Actions

Russia’s intensified intelligence operations near Japan seem driven by two primary strategic goals:

1. Gathering U.S. Military Communications for the Ukraine War

The war in Ukraine has underscored the importance of real-time intelligence. U.S. military assets in the Indo-Pacific region, including those in Japan, are heavily involved in satellite communications and data relay operations. Russia likely aims to intercept, analyze, and exploit these communications to enhance its understanding of U.S. military movements, electronic warfare capabilities, and broader strategic intentions. This information can then support Russian operations not just in Ukraine but in global theaters where U.S. influence is critical.

2. Addressing Russia’s Heightened Security Anxiety

Amidst deteriorating relations with NATO, Europe, and the United States, Russia’s threat perception has expanded significantly. Its increased activities around Japan reflect broader defensive paranoia—seeking to preemptively gather intelligence that could be critical if tensions in the Indo-Pacific escalate. This is especially pertinent given the strengthening of U.S.-Japan military cooperation and Japan’s increasing security alignment with the United States and other Western powers.