Malabar 2026 Kicks Off, Naval Cooperation Among Four Countries Changes Underwater Warfare Near Japan

On November 5, the opening ceremony of Malabar 2026 was held at Yokosuka, featuring the destroyer "Ise." The annual maritime exercise involving Japan, the United States, Australia, and India (Quad) will continue until November 12, with participation from the Japan Maritime Self-Defense Force's destroyers and submarines, as well as vessels from the U.S., Australia, and India. This is not an event to compete in the number of vessels. What to observe this time is how navies, which differ in peacetime, connect the domains of surface, underwater, air, and information using the same procedures.

What the 30th Year Exercise Tests

According to the U.S. Pacific Fleet, Malabar began in 1992 as a small bilateral event between the U.S. and India and has now reached its 30th anniversary in 2026. This is the sixth time all four countries have participated. From the U.S. side, the P-8A Poseidon maritime patrol aircraft, and the San Antonio-class dock landing ships "Anchorage" and "John P. Murtha" will join, conducting both shore and at-sea training around Yokosuka.

This composition cannot be explained merely by a "containment of China" framework. By combining the P-8A with JMSDF submarines, it is possible to repeatedly connect the acoustic information necessary for submarine detection and tracking with aerial surveillance. The participation of landing ships indicates that the training scope has expanded to protect not only sea lines of communication (SLOC) but also the transportation of troops and supplies to island areas. U.S. Navy Seventh Fleet Commander Patrick Hannifin emphasized interoperability and trust that allows for joint operations at sea, in the air, and underwater.

The Significance of Conducting Exercises Near Japan

Conducting Malabar, which has been held in the Indian Ocean, in the southern waters of the Japanese archipelago has geographical significance. For Japan, it allows for the verification of the Indian Navy's long-range deployment capabilities and Australia's operational experience in the same maritime area, centered around the U.S.-Japan alliance. For India, it provides an opportunity to continuously demonstrate naval interest in the East China Sea and the Western Pacific.

However, it is premature to directly equate the success of the exercise with joint operational capabilities in a crisis. Communication standards, rules of engagement, logistics, and the scope of sharing classified information cannot be fully aligned in a short training period. More important than the symbolism of approximately 200 people gathering at the opening ceremony in Yokosuka is how quickly submarine contact information can be shared and who will take over the tracking mission.

Overlooked Risks

While the cooperation among Japan, the U.S., Australia, and India enhances deterrence, it does not guarantee that the political will of the participating countries will move at the same pace. Even if communication and coordination are established in peacetime, there is no assurance that India will accept the same operational objectives in a crisis. The true metric to gauge in this Malabar 2026 is not the glamour of the vessels but the "distributed trust" that allows each country to maintain its own judgment while sharing limited information.

Main Sources Referenced

• NHK WORLD-JAPAN "Quad nations start maritime exercise" November 5, 2026
• U.S. Pacific Fleet "Funakoshi hosts forces from Australia, India, Japan and U.S. for start of exercise Malabar 2026"
• USNI News "U.S., Partner Nations to Hold Annual Malabar Naval Exercise Near Japan" October 29, 2026