India’s long-delayed but strategically critical Project-75I is now emerging as one of the most consequential defence programmes in the Indo-Pacific. Valued at nearly $8 billion, the project aims to induct six next-generation conventional submarines equipped with advanced stealth, sensors and air-independent propulsion (AIP). Beyond modernisation, Project-75I is fundamentally about reshaping India’s undersea deterrence posture especially against a two-front maritime challenge from Pakistan and China.
What Is Project-75I?
Project-75I is an extension of India’s earlier Scorpène (Project-75) programme but with a crucial upgrade: AIP technology, which allows submarines to remain submerged for weeks without surfacing. This dramatically improves survivability and lethality, particularly in contested waters like the Arabian Sea and the Indian Ocean Region (IOR).
The submarines will be built in India under the Strategic Partnership model, with an Indian shipyard collaborating with a foreign original equipment manufacturer. This aligns with New Delhi’s broader push for defence indigenisation while ensuring access to cutting-edge underwater warfare technology.
Why It Matters Against Pakistan
For Pakistan, submarines are the backbone of its naval deterrence. Islamabad operates French-origin Agosta submarines and is inducting Chinese-built Hangor-class (Type-039B) submarines, many of which will also feature AIP. These platforms are designed to threaten India’s western seaboard and sea lines of communication.
Project-75I significantly tilts the balance back in India’s favour. The new submarines’ superior endurance, quieter signatures and advanced combat systems would allow the Indian Navy to track, deter or neutralise Pakistani submarines before they pose a credible threat. In a crisis, this undersea advantage could limit Pakistan’s ability to escalate at sea while protecting India’s ports, energy routes and naval assets.
The Bigger Challenge: China in the Indian Ocean
While Pakistan is an immediate concern, China is the long game. The People’s Liberation Army Navy (PLAN) has steadily expanded its submarine deployments in the IOR under the guise of anti-piracy missions. Chinese nuclear and conventional submarines have been sighted in and around India’s maritime neighbourhood, supported by ports and facilities developed under the Belt and Road Initiative.
Project-75I strengthens India’s ability to deny China freedom of manoeuvre in the IOR. Advanced Indian submarines can operate as stealthy “sea-denial” assets, tracking Chinese vessels and complicating Beijing’s plans to project power far from its shores. When combined with India’s growing network of maritime partnerships through the Quad and bilateral naval exercises the deterrent effect multiplies.
Strategic Signalling and Deterrence
Beyond hardware, Project-75I sends a powerful strategic signal. It underscores India’s intent to remain the primary undersea power in the Indian Ocean, capable of handling simultaneous challenges. It also complements India’s nuclear submarine programme, creating a layered deterrence architecture spanning conventional and strategic platforms.
Challenges Ahead
Despite its promise, Project-75I faces hurdles: cost escalation, technology transfer negotiations, and delays in finalising the foreign partner. Any further slippage risks widening the capability gap as Pakistan and China continue to induct new submarines at pace.
The Bottom Line
Project-75I is not just a procurement exercise it is a geopolitical lever. If executed on time, it will significantly enhance India’s maritime deterrence, blunt Pakistan’s undersea ambitions, and complicate China’s expanding footprint in the Indian Ocean. In an era where silent power beneath the waves can shape outcomes above them, India’s $8-billion bet could prove decisive.
