The destroyer Kaga begins F-35B landing and takeoff training on June 4, advancing the maritime air operations of the Japan-U.S. alliance to a combat stage.
Tanaka TakashiThe Destroyer Kaga Begins F-35B Landing and Take-off Training on June 4, Advancing U.S.-Japan Alliance Maritime Air Operations to Combat Readiness
On June 4, a U.S. Marine Corps F-35B will head to the flight deck of the Kaga in the Western Pacific. The Japan Maritime Self-Defense Force (JMSDF) announced on May 28 with a simple one-page document. However, the three terms written there—"JS KAGA," "F-35B," and "Deck Landing and Take-off Training"—indicate that Japan's maritime air operations are moving from the testing phase to the phase of allied operations.
According to the Maritime Staff Office, the forces of the Indo-Pacific Deployment 2026 (IPD26) will conduct joint training with the U.S. Marine Corps from June 4 to 12. The purpose is to enhance the JMSDF's tactical skills and strengthen relations with the U.S. Marine Corps, with the training area being the Western Pacific, and the participating units being the destroyer Kaga of the IPD26 Second Surface Unit and the U.S. Marine Corps F-35B.
Operational Changes Indicated by a Brief Announcement
The significance of this training should not be dismissed simply as "aircraft carrier conversion." Rather, what is noteworthy is that the JMSDF is repeatedly conducting landing and take-off training with U.S. Marine Corps aircraft despite not possessing F-35Bs. As the Japan Air Self-Defense Force (JASDF) maintains its F-35B units separately from the JMSDF's shipboard operational foundation, the U.S. Marine Corps is serving as a practical bridge connecting the two.
USNI News reported on May 20 that the Kaga would call at Iwakuni Air Base from June 1 to 4 to load equipment for the U.S. Marine Corps F-35B. It is unusual for a Japanese destroyer to call at Iwakuni, and it is said that the Iwakuni city side requested consideration for resident concerns and that the base not become a permanent port of call. Here, operational rationality and local political tensions are simultaneously reflected.
Specifications of Kaga and the Reality of F-35B Operations
The Kaga is the second ship of the Izumo-class destroyers, measuring approximately 248 meters in length and displacing about 19,500 tons, making it one of the largest vessels in the JMSDF. The F-35B is capable of short take-off and vertical landing, and the U.S. Marine Corps has operated it from amphibious assault ships and forward-deployed bases. When operating this aircraft from a JMSDF ship, issues arise regarding deck heat resistance, aviation fuel, ammunition management, landing and take-off control, rescue systems, and maintenance space.
- Training Period: June 4 to 12, 2026
- Training Area: Western Pacific
- Participating Units: JMSDF Destroyer Kaga, U.S. Marine Corps F-35B
- Training Content: Landing and take-off training on the deck
- Operational Focus: Shipboard air operations, U.S.-Japan joint procedures, forward deployment capabilities
In the author's view, the essence of this training lies not in the number of F-35Bs that the Kaga can carry, but in how much the maintenance and re-deployment time can be compressed before and after landing and take-off. Simply placing an aircraft on the flight deck may suffice as a political symbol. However, what holds significance in actual combat is whether air operations can be sustained at a certain tempo under conditions such as inclement weather, nighttime, damage, communication restrictions, and delays in refueling.
Connection to the Defense of the Southwestern Islands
The reason Japan introduced the F-35B is not merely to adapt large destroyers for fixed-wing aircraft. In the vicinity of the southwestern islands, the continuation of air operations in the event of runway damage is always a concern. Short take-off and vertical landing aircraft can be operated from dispersed bases or, when conditions permit, from maritime platforms. This flexibility becomes a factor for the U.S.-Japan alliance to handle air superiority and maritime control without separating them as the activities of the Chinese Navy and Air Force expand beyond the first island chain.
At the same time, the Kaga is scheduled to operate alongside the destroyer Fuyuzuki and the supply ship Mashu as part of the IPD26 Second Surface Unit, and it has been reported that it will also participate in RIMPAC 2026 hosted by the U.S. Third Fleet starting in late June. This is not a test of a single ship but part of a long-range deployment that includes supply, escort, and connection with allied fleets. While the JMSDF during the Cold War focused on SLOC (Sea Lines of Communication) defense, the current JMSDF has no choice but to consider SLOC defense and forward air operations on the same operational map.
Institutional Discrepancies Behind Strengthening the Alliance
However, excessive expectations should be avoided. Japan's F-35B is equipment of the JASDF, while the JMSDF operates the ship. It is reasonable for the U.S. Marine Corps to be the immediate training partner, but for Japan to complete shipboard fixed-wing operations independently, it is necessary to clarify responsibilities regarding personnel training, maintenance qualifications, air traffic control, accident investigation, and ammunition supply.
Furthermore, the local response regarding the Iwakuni port call is a microcosm of the challenges that will arise in the southwestern islands and Kyushu in the future. The use of bases and ports can be connected on paper through operational plans. However, in reality, it involves local government explanations, noise, port usage, resident concerns, and the division of responsibilities between the U.S. military and the Self-Defense Forces. This is a problem that cannot be resolved by equipment performance alone.
The F-35B training on the Kaga is not a theological debate about whether Japan possesses an aircraft carrier, but a practical issue of how quickly the U.S. and Japan can restructure air operations in the Western Pacific.
Conclusion
This landing and take-off training represents a significant step for the JMSDF. However, the true focus is not on the shape of the ship or the performance of the F-35B. It is whether the JMSDF, JASDF, U.S. Marine Corps, local governments, and supply sectors can operate on the same clock during a crisis. If adjustments on land are delayed by several days, the operational maneuvering will not be feasible, regardless of the few minutes on the deck. This is the unresolved risk that this training quietly presents.
Major Information Sources
The Japan Maritime Self-Defense Force's JS Kaga will conduct joint training exercises with U.S. Marine Corps F-35B aircraft in the Western Pacific from June 4 to June 12, 2026. This training focuses on deck landing and take-off operations, enhancing Japan's tactical skills and strengthening U.S.-Japan military relations. The exercises represent a significant advancement in Japan's naval aviation capabilities.
- The JS Kaga will conduct joint training with U.S. Marine Corps F-35B aircraft from June 4 to June 12, 2026.
- The training aims to enhance Japan's tactical skills and strengthen relations with the U.S. Marine Corps.
- The exercises will take place in the Western Pacific region.
- The JS Kaga is Japan's largest destroyer, measuring approximately 248 meters in length.
- The training involves deck landing and take-off operations, marking a significant step in Japan's naval aviation capabilities.