Northeast Asia Air Defense with Six Destroyers from Japan, the U.S., and South Korea in Freedom Edge 2026

In September, the "Freedom Edge 2026" exercise was conducted in the southeastern airspace of the Korean Peninsula and at bases within Japan. Six destroyers, fighter jets, helicopters, patrol aircraft, and aerial refueling aircraft were deployed for this exercise. A senior officer from the Japan Maritime Self-Defense Force (JMSDF) participated in the exercise control, and for the first time, cyber defense was also addressed at the command center in Yokota, marking a departure from traditional maritime joint training.

The Meaning of "Six" is Not Just the Number of Vessels

According to the published materials, the training items included ballistic missile defense, air defense, maritime interdiction, at-sea replenishment, search and rescue, medical evacuation, and real-time information sharing. This is not merely about the three countries lining up their vessels in the same maritime area. It is a training exercise to test whether they can connect detection, identification, engagement decision-making, replenishment, and casualty transport along a single timeline.

In response to North Korea's nuclear and missile capabilities, the air defense cooperation among Japan, the U.S., and South Korea is believed to have progressed beyond mere information sharing to a stage where they compete in synchronizing decision-making. For Japan, the focus will be on how quickly the JMSDF's escort ships can incorporate sensor information from South Korea into operations while operating in both the Sea of Japan and the East China Sea.

New Pressure from North Korea's New Destroyer

This exercise coincided with the period when North Korea commissioned the destroyer "Kang Gon," which is assumed to be capable of nuclear operations. There are still many unknowns regarding the ship's actual operational capabilities and onboard weapons, making it dangerous to evaluate it at face value. However, even politically demonstrating missile operations from a maritime platform will force Japan, the U.S., and South Korea to revise their traditional land-based launch-centric monitoring plans.

It is important to note that Freedom Edge is not solely focused on North Korea. The simultaneous testing of destroyer air defense, patrol aircraft surface monitoring, aerial refueling endurance, and communication network resilience can also be applied to the protection of SLOCs (Sea Lines of Communication) extending from the East China Sea to the Sea of Japan. In a context where the activities of the Chinese Navy are increasing, if Japan, the U.S., and South Korea can maintain a common situational picture, it will have a greater effect than merely increasing the number of individual patrol vessels.

The Alliance's Weakness Lies in Operations, Not Politics

However, the success of the exercise should not be directly equated with operational cooperation in real combat. If the political relationship between Japan and South Korea wavers again, there remains the possibility that the speed and scope of information sharing could diminish. Additionally, the burden of consistently securing support vessels, maintenance personnel, interpreters, and data link personnel to support the six destroyers cannot be overlooked. The number of personnel who can repetitively execute the same procedures in peacetime will be a constraint more significant than the number of vessels.

What Freedom Edge 2026 demonstrated is not a conclusion that Japan, the U.S., and South Korea have become integrated. Rather, it indicates that a minimum circuit has finally extended to the maritime domain to prevent the three countries from making separate judgments in the first few hours of a crisis.

Sources

• Indo-Pacific Defense Forum, “Japan, ROK, U.S. Boost Interoperability and Deterrence in Freedom Edge Exercise”
• Eurasia Review, Article published on September 28, 2026
• Japan Maritime Self-Defense Force Official Press Release