India has accumulated experience organically and in public, through blood, sweat and toil -- one commissioning and one agreement at a time -- and is called a regional power.
China has accumulated hulls, by misdirecting its industrial capacity, and is mistakenly called a superpower.
The Indo-Japan defence agreement pushes this theory to its limits without ever naming the dragon in the room, points out Dr Abhishek Puri.
Key Points
- India and Japan are strengthening maritime cooperation through information sharing, search and rescue, and humanitarian assistance.
- India has signed submarine rescue agreements with Singapore, South Africa, Australia and Vietnam since 2021.
- India's Nistar and Nipun vessels have expanded the Indian Navy's submarine rescue and saturation diving capabilities.
- Japan already operates dedicated submarine rescue vessels, making information sharing a more significant potential benefit.
- The expanding rescue network gives India greater operational connectivity across the Indo-Pacific maritime domain.
Tezuma -- the Japanese tradition of sleight of hand -- is usually accompanied by elements of Kabuki: Dance, formalised kata, and mitate, the device by which one object is made to represent another, a sheet of paper becoming a living butterfly.
Those elements are the necessary context for reading the joint press statement (external link), which strengthens cooperation between the Japan Maritime Self-Defense Force and the Indian Navy, 'including information sharing in the field of Maritime Domain Awareness (MDA), as well as enhanced cooperation in areas such as Search and Rescue (SAR) and Humanitarian Assistance and Disaster Relief (HADR)' -- especially when the audience is the Chinese PLA, exclusively.
MDA is the latch; SAR and HADR are bolted to it. Maritime domain awareness between two navies means a continuously shared surface and subsurface track picture, and anti-submarine warfare is fundamentally an information domain, won by whoever holds the better cumulative picture.
SAR is the euphemistic container that lets continuous MDA sharing exist without either government describing it, and without Japan's constitutional constraints or India's non-alignment posture being tested in public.
The rest of the joint document reaffirms the naval context repeatedly: sea-lane protection, mutual port access, and a reciprocal ship-repair arrangement.
Flexing the capability
India has spent five years signing submarine rescue instruments -- with Singapore (external link) in January 2021, South Africa (external link) in September 2024, Australia (external link) in October 2025 and Vietnam (external link) a month later. Japan is absent from the list.
Incompatible fleets are not the question, because crew rescue was standardised precisely so that it would not depend on common fleets.
Singapore runs ex-Swedish and German boats, South Africa German Type 209s, Australia the Swedish-designed Collins; only Vietnam shares India's Kilos.
Vessels certified to STANAG 1297 mate with any hull carrying a compliant seat, and ATP-57 (external link) supplies the documentation layer.
The real constraint is supply, because of cost and difficulty. A vessel that can locate a bottomed submarine, mate with a hatch canted at up to 45 degrees and transfer crew under pressure -- equipped with a saturation diving system and a hyperbaric chain -- requires considerable expertise.
Bharat joined this exclusive club in 2018, then augmented the capability with Nistar and Nipun, launched together (external link) at Hindustan Shipyard in September 2022.
INS Nistar was delivered in July 2025 (external link) and commissioned days later (external link), capable of saturation diving to 300 metres and serving as mother ship. Her sister followed in 2026.
This capability has a remarkable overlap with the agreements. In September 2025 Nistar made her maiden foreign port call at Changi for Exercise Pacific Reach (external link) , where India's Submarine Rescue Unit (East) achieved three successful matings with foreign submarines (external link) over three days. Australia signed in October. Vietnam signed in November.
Why Japan would want one anyway
Does Japan want access to submarine rescue? Most likely not. The Japan Maritime Self-Defense Force has operated its own DSRVs with dedicated mother ships -- Chihaya and Chiyoda (external link) -- for decades, and hosted Pacific Reach in 2002 (external link) , when India attended only as an observer. Tokyo is not queuing for a capability it pioneered in the region.
The value of such an arrangement, therefore, lies in the standing apparatus that rescue requires: Pre-cleared access for foreign vessels into each other's operating areas, and a secure channel for passing submarine positions in real time.
These remain classified in the public domain and are guarded most closely. A humanitarian cover for 'search and rescue' is simply the frame that permits the exchange.
The untested navy
Western media -- and perhaps the American assessment -- considers China an emerging naval superpower on the basis of hull count (external link).
Its warfighting capability is far less known. Beijing has been caught recruiting retired Royal Air Force and Australian Defence Force pilots (external link) , at fees reported above Pound 240,000, to instruct PLA aviators -- an odd requirement for a force with mature instructional doctrine of its own.
Its submarine warfare tactics remain unaccounted for. China is, for practical purposes, a black box that masks its true capabilities.
The rescue lattice measures what tonnage cannot. Each instrument required two navies to agree procedures, exchange sensitive data, rehearse together, and admit foreign assets into their own exclusive maritime domain.
China did attend Pacific Reach 2025 (external link).
It has not, however, built the reciprocal web that lets a fleet operate far from home knowing that someone else's asset covers the gap.
India has accumulated this experience organically and in public, through blood, sweat and toil -- one commissioning and one agreement at a time -- and is called a regional power.
China has accumulated hulls, by misdirecting its industrial capacity, and is mistakenly called a superpower.
The Indo-Japan defence agreement pushes this theory to its limits without ever naming the dragon in the room.
Tezuma is judged not by whether the trick deceives, but by the precision of the kata that carries it.
This statement is a well-executed form, and every navy watching the Indo-Pacific knows precisely which object has become which.
Feature Presentation: Aslam Hunani/Rediff
