The Cancellation of Training with the Destroyer Kaga and F-35B Highlights the Fragility of U.S.-Japan Carrier Operations in 2026

A brief announcement issued by the Maritime Staff Office on May 30 abruptly erased the larger picture that had been anticipated. The joint training exercise between the destroyer "Kaga" and the U.S. Marine Corps F-35B, scheduled to take place in the Western Pacific from June 4 to 12, was canceled due to operational considerations and the possibility of inclement weather. The announcement was only a few lines long and did not mention any alternative dates. However, this silence seems to weigh more heavily on the author.

The Significance of the Planned Training

According to the Maritime Staff Office's announcement on May 28, the participating units were the "Kaga" from the IPD26 Second Surface Group and the U.S. Marine Corps F-35B. The training items were to include takeoff and landing exercises, with the aim of improving the Japan Maritime Self-Defense Force's tactical skills and strengthening relations with the U.S. Marine Corps. On the surface, it appeared to be a routine joint exercise, but in reality, it was an opportunity to assess how closely the refurbished "Kaga" could be utilized in a manner similar to actual operations by both Japan and the U.S.

USNI News reported on May 20 that the "Kaga" was scheduled to dock at Iwakuni Air Base from June 1 to 4 and would be equipped with gear related to the operation of the U.S. Marine Corps F-35B. This means that the training was not merely about landing aircraft on the deck. It was likely a test that combined maintenance equipment, control procedures, fuel, deck personnel, and communication with U.S. aviation units into a single flow.

Inclement Weather is Not an Exception but a Design Condition

The inclusion of "the prospect of inclement weather" as a reason for cancellation should not be dismissed as mere bad weather. The F-35B's short takeoff and vertical landing are strongly influenced by wind direction, deck motion, visibility, engine reserve, and deck temperature. Even for U.S. Navy and Marine Corps amphibious assault ships, weather conditions can determine the feasibility of training. Moreover, the "Kaga" is a ship that has been modified to accommodate the F-35B based on a helicopter-carrying destroyer, and it is not a vessel that has routinely accepted U.S. Marine Corps carrier aviation.

What is important here is not the fact that the weather was bad, but that when combining limited schedules, limited ships, and limited U.S. Marine Corps F-35B units, a single cancellation can have a significant impact on the entire training cycle. For the Japan Maritime Self-Defense Force to operate the Air Self-Defense Force's F-35B stably from the "Izumo" and "Kaga" in the future, the ability to reschedule in bad weather will be more critical than the success stories in good weather.

The Concept of 42 Aircraft and the Distance to Deck Operations

Japan plans to introduce a total of 42 F-35B aircraft, with Nittahara Air Base as the center. The AP reported that the F-35B will be operated from the "Izumo" and "Kaga," and that the training facility on Mageshima will be delayed until around 2030, necessitating continued training at Nittahara Air Base for the time being. On paper, the 42 aircraft and the two modified ships appear to align.

However, carrier operations cannot be established by numbers alone. Qualified pilots, air traffic control, maintenance personnel, ammunition and fuel resupply, night operations, damage recovery, and command relationships between the Maritime Self-Defense Force and the Air Self-Defense Force are all necessary. Training for takeoffs and landings conducted with U.S. Marine Corps aircraft serves as a shortcut to fill this gap, while also indicating the dependency until Japan acquires independent carrier aviation capabilities.

Has the Deterrent Signal to the Chinese Navy Weakened?

In the short term, it is unlikely that this cancellation will change the actions of the Chinese Navy. In late May, the Chinese aircraft carrier "Liaoning" strike group was active in the Philippine Sea east of Luzon, and Japan was monitoring its movements. As China increases the frequency of carrier operations in the Western Pacific, Japan's deployment of F-35B-capable destroyers carries symbolic significance for the defense of SLOCs (Sea Lines of Communication) from the southwestern islands to the Philippine Sea.

However, deterrence cannot be maintained by symbolism alone. What the adversary sees is not the ship's name but the repeatable capability. While the cancellation of a single takeoff and landing training does not negate capability, at a stage where schedules can easily disappear due to weather and operational considerations, "carrier-like operations" have not yet fully transcended the realm of political messaging.

Practical Challenges Remaining for the Maritime Self-Defense Force

• Securing training opportunities for the "Kaga" and "Izumo" without being overly dependent on the U.S. Marine Corps' convenience.
• Documenting alternative maritime areas, alternative schedules, and readjustment procedures for Iwakuni, Nittahara, and the fleet during inclement weather.
• Integrating command and control between the Air Self-Defense Force's F-35B units and the Maritime Self-Defense Force's destroyer fleet not only during exercises but also from the planning stage in peacetime.
• Developing deck personnel and aviation maintenance personnel not as temporary training support but as continuous carrier aviation personnel.

In the author's view, this cancellation is not a failure. Rather, it is a friction that naturally arises during the process of forming practical capabilities. The issue is whether this will be treated as a "cancellation due to weather" or seen as "the U.S.-Japan light carrier operations are still tied by a thin thread."

The real challenge is not whether the F-35B can land on the "Kaga." It lies in whether Japan can maintain enough operational depth to reorganize the next training within a few days, even when faced with bad weather, political schedules, and the redeployment of U.S. forces.

Key References

• Japan Maritime Self-Defense Force, Cancellation of Japan-U.S. Bilateral Exercise, May 30, 2026
• Japan Maritime Self-Defense Force, Japan-U.S. Bilateral Exercise, May 28, 2026
• USNI News, Japan’s Largest Warship Preparing for F-35B Training with U.S. Marines, May 20, 2026
• AP News, Japan deploys its first F-35B fighter jets to bolster defenses in the south, August 7, 2025