India’s economic ambitions travel across the sea, but their security increasingly depends on what can remain hidden beneath it. The movement of Project-75(I) towards a final government decision therefore carries significance beyond the acquisition of six submarines. It tests India’s ability to translate maritime vulnerability into sustained military capability and a stronger domestic industrial base.
According to reports, the proposal, estimated at more than ₹80,000 crore, had reached the final stage. In remarks to the media, Defence Secretary Rajesh Kumar Singh said: “Both Project-75(I) and additional Scorpene submarines are being considered. Project-75(I) is at the final stage.” The distinction matters: neither proposal should be presented as a concluded acquisition.
The anticipated partnership between Mazagon Dock Shipbuilders Limited and Germany’s TKMS would combine domestic construction with foreign technology under the Strategic Partnership framework. Three additional Scorpene submarines are separately under consideration. These are potentially complementary decisions, although their contracts, delivery schedules and production arrangements remain to be settled.
The operational argument is compelling. Submarines create uncertainty for an adversary because their location and intentions are difficult to establish. They can gather intelligence, threaten hostile vessels and complicate attempts to dominate maritime approaches. Their deterrent effect extends beyond the weapons they carry: an opposing fleet must devote resources to finding and tracking them.
Air-independent propulsion is central to the proposed capability enhancement. DRDO explains that AIP significantly increases the submerged endurance of diesel-electric submarines. Longer endurance can reduce exposure and widen operational choices. However, propulsion alone does not determine effectiveness. Sensors, weapons, acoustic performance, crew proficiency and maintenance availability together shape the combat value of a submarine.
The wider strategic context becomes clear in the Indian Ocean, where securing sea routes is essential to India’s prosperity and the functioning of international commerce. Recently, at a conference in New Delhi, Navy Chief Admiral Krishna Swaminathan noted that nearly 90% of India’s trade by volume and over 70% by value moves by sea. He also cited approximately 100,000 annual ship transits through the region, carrying about 30% of global containerised cargo and more than half of the world’s crude oil.
These figures explain why maritime disruption reaches far beyond coastal communities. Threats around Hormuz, Bab el-Mandeb or routes towards Malacca can affect energy supplies, freight costs, industrial inputs and export competitiveness. Defence Minister Rajnath Singh captured this connection in January 2025: “India’s economic prosperity is linked to maritime security.” Securing the ocean is consequently an economic requirement as much as a military responsibility.
Swaminathan’s recent warning sharpened the urgency: “Between 40 and 50 warships from extra-regional navies maintain a presence in the region almost perpetually.” He also identified missiles and unmanned systems among the evolving threats, including technologies accessible to non-state actors. Persistent foreign naval presence increases the demands on surveillance, readiness and underwater deterrence.
Submarines, however, cannot independently secure commercial shipping across this vast theatre. Merchant protection also requires surface ships, maritime aircraft, intelligence cooperation, surveillance networks and diplomacy. Project-75(I) should strengthen this integrated architecture, giving India greater capacity to deter hostile action while other assets maintain visibility and protect vulnerable shipping.
The industrial stakes are equally substantial. Submarine construction depends on specialised skills that take years to develop: precision fabrication, systems integration, rigorous testing and safety assurance. A production interruption risks dispersing experienced workers and weakening suppliers. Additional Scorpenes could provide continuity at MDL, but only if their timing actually bridges the interval before the larger programme enters production.
The proposed German partnership should therefore be assessed through the capabilities India retains over the submarines’ operating lives. Domestic construction is valuable, but durable autonomy also requires access to maintenance knowledge, dependable spares, upgrade pathways and meaningful participation by Indian suppliers. Contractual arrangements must support these outcomes rather than merely maximise the initial localisation headline.
India should simultaneously advance indigenous underwater technologies. DRDO’s AIP development for Project-75 submarines illustrates how foreign partnerships and domestic research can reinforce each other. The policy challenge is to ensure that successive programmes deepen Indian competence, allowing industry to move towards greater responsibility for design, integration and sustainment.
At this scale of expenditure, procurement discipline is indispensable. Clear milestones, realistic delivery commitments, transparent allocation of industrial responsibilities and adequate provision for training and maintenance should accompany any approval. The Navy needs usable operational capability, which depends on available boats and prepared crews throughout the fleet’s service life.
The government’s decision will thus carry consequences for security, manufacturing and economic resilience. Approval would begin another demanding phase of negotiation, construction and induction. India’s task is to convert the proposal into dependable underwater strength while preserving the industrial expertise needed to sustain it. In an increasingly militarised Indian Ocean, that combination will help protect both national interests and the maritime networks supporting India’s growth.
