Exercise Malabar began as a bilateral exercise between:

Australia and the United States

Malabar 2026 at Yokosuka: How Four Navies Practise Working Together

Why in news?

The navies of India, Japan, the United States and Australia gathered at Yokosuka for Exercise Malabar 2026. India’s INS Sahyadri arrived on 4 November, according to the Defence Ministry. A US Navy report published on 5 November described the opening ceremony, followed by scheduled activities ashore and at sea. Japan’s Maritime Self-Defense Force also reported the opening and a meeting of the participating naval commanders.

How the exercise developed

Malabar began in 1992 as a bilateral exercise between India and the United States. Japan became a regular participant in 2015. The 2020 edition brought together all four navies. The exercise has developed into a setting for multilateral planning, professional interaction and coordinated training.

A bilateral exercise involves two countries. A multilateral exercise brings several countries into the same activity. The larger format requires participating forces to coordinate their plans and procedures across more than one national system.

Why the harbour phase matters

The Indian announcement describes a harbour phase involving professional interactions and coordinated planning. This gives participants time to discuss the activities, exchange expertise and prepare for work at sea. Common understanding is important when different ships and aircraft must carry out connected tasks.

For example, a detected object may have to be reported to several units. Those units need to understand the report, its location and its relevance to the planned activity. Agreed procedures and communication practices help them interpret information consistently and coordinate their response.

What interoperability means

Interoperability is the ability of different forces and their systems to work together effectively. It combines people, procedures, communications and equipment. A joint exercise provides a controlled setting in which participants can practise these connections and identify where further coordination is needed.

The US Navy account says the planned sea training includes surface, subsurface, air and information domains. These refer to activities involving ships, the underwater environment, aircraft and information systems. Coordinating across domains links the work of several kinds of unit within a common training plan.

India’s participating ship

INS Sahyadri is an indigenously built guided-missile stealth frigate of the Indian Navy’s Eastern Fleet. The 5 November Indian release identifies it as the ship participating in Malabar. It will work with units from the other participating countries during the sea phase described in that announcement.

Locating Yokosuka

Yokosuka lies on Japan’s Pacific side, on Honshu, south of Tokyo. The city describes its port as lying on the southwest side of Tokyo Bay. Its coastline contains several inlets that provide sheltered harbour areas. The map places Yokosuka within Japan and the surrounding seas.

Regional map highlights Japan and locates the general Yokosuka area on the Pacific side of Honshu, with the surrounding seas and a world overview. — Yokosuka is on the southwest side of Tokyo Bay. General locator; Clarity original map, sources: Yokosuka City and Natural Earth and DataMeet (CC BY 4.0).

A naval exercise connects this harbour setting with training in nearby waters. Shore activities support planning and professional exchange, while the sea phase lets units practise operating together. Reading the phases in sequence helps explain how an exercise moves from preparation to coordinated activity.

Conclusion

Malabar links four naval partners through planning and practical training. Its focus on interoperability explains why communication, shared procedures and coordination matter alongside the ships and aircraft taking part.