Submarine supremacy: India must pursue it to project power across the Indian Ocean region

Missile and drone strikes on US military installations across the Gulf region and Israeli operations reaching deep into Lebanon have further expanded the theatre; today, the distinction between the West Asia war and Indian Ocean crisis has effectively ceased to exist.

But it pays to look at what lies beneath the surface—that is, under the carrier battle groups, destroyer formations and mine-countering operations.

The latest war’s basic lesson: The current war has taught the world a critical truth: the ocean is no longer a free waterway for ships to traverse. Decades of uncontested American maritime supremacy had allowed us to treat it as such, even take maritime movement for granted. Cargo and passengers moved freely; oil flowed without interruption; trade expanded unchecked. But this year’s US-Israeli conflict with Iran has turned the Indian Ocean into an active theatre of hostility with no end in sight.

By late April, many vessels had been attacked in Gulf waters—struck by missiles, drones and torpedoes—forcing insurers, shipping companies and commodity traders to fundamentally rethink the safety of the world’s most critical trade corridors. Global trade has not merely been disrupted, its character has changed, and the scars of the conflict will outlast any ceasefire by decades.

Less visible but far more consequential is the role that submarine deployments and the threat of submarine-launched attacks have played in reshaping strategic calculations across the region. The presence of even a single unlocated hostile submarine creates strategic paralysis, forcing defending navies to concentrate on defensive resources, modify operational patterns and limit the freedom of manoeuvre that surface vessels need.

Iran’s deployment of its diesel-electric submarines has injected a degree of uncertainty into every US-led naval operation. For the first time in the modern era, a numerically inferior naval force, equipped with advanced submarine technology, has effectively constrained the operations of vastly superior surface fleets.

Comprehensive naval dominance is a strategic imperative for India: India’s position as a regional power is inextricably linked to its capacity to maintain uncontested maritime supremacy in the Indian Ocean. The region accounts for nearly 40% of global maritime trade and multiple critical shipping routes converge in these waters, even as energy flows pass through chokepoints vulnerable to interdiction. India’s economic growth depends on the security and freedom of these sea lanes.

The war in West Asia and the Indian Ocean is reshaping global maritime strategy in real time. It has demonstrated that surface naval power—however formidable—is incomplete without advanced submarine capabilities. It has shown that strategic dominance in the maritime domain requires integrated operations across surface, subsurface and air dimensions. And it has it made unmistakably clear that nations without comprehensive maritime power are vulnerable to coercion, interdiction and worse.

For India, which has one of the world’s most strategically consequential oceans around it and remains heavily dependent on its waterways for progress, stepped up naval investment is a strategic necessity.

Our economic growth, energy security, regional dominance and national sovereignty will increasingly rely on the country’s ability to project power across the Indian Ocean in order to serve its strategic interests. The investment outlay must prioritize submarines, for these are the key instrument of maritime power.

In a fractured world where old certainties are falling apart, we must move quickly. The world is watching. Will India act?

The authors are, respectively, a retired Indian Navy veteran; and an author.