Beneath the waves: Where India stands in a 2-front submarine war with China and Pakistan

In modern naval warfare, the decisive contest is often invisible. Beyond the frigates, destroyers and aircraft carriers that signal power above the surface, the most lethal deterrent operates in silence beneath it.

From Jules Verne’s imagined Nautilus in Twenty Thousand Leagues Under the Sea — commanded by the enigmatic Captain Nemo — to today’s nuclear-powered fleets, submarines have evolved into silent hunters like sharks, moving unseen through the depths and serving as one of the most formidable pillars of strategic deterrence sometimes with nuclear weapons.

As tensions rise across the Indo-Pacific, the underwater balance between India, China and Pakistan is becoming a decisive strategic variable. 

Numbers game: Who has what? 

China: The Undisputed Undersea Giant 

• Total submarines: 60+ 
• Nuclear-powered: 10-14 (SSNs + SSBNs) 
• Conventional (diesel-electric): 50 

China’s People’s Liberation Army Navy (PLAN) is not just the largest navy in the world — it is rapidly transitioning toward an all-nuclear submarine fleet, enhancing endurance and global reach. 

India: A Balanced but Smaller Force 

• Total submarines: 19 
• Nuclear-powered: 3 SSBNs (Arihant-class) 
• Conventional: 16 diesel-electric 

India’s nuclear fleet includes: INS Arihant, INS Arighat and INS Aridhaman. India lacks operational nuclear attack submarines (SSNs) of its own (leased ones aside), which is a critical gap in offensive underwater capability. 

Pakistan: Smaller but Sharpening Its Edge 

• Total submarines: 5-8 (current + incoming) 
• Nuclear-powered: 0 
• Conventional: Agosta-class + incoming 8 Chinese Yuan-class (AIP-equipped) 

Pakistan’s strategy is clear: quality over quantity, with heavy focus on Air-Independent Propulsion (AIP) submarines that can stay submerged longer and operate stealthily in the Arabian Sea. 

Technology Divide: Nuclear vs Conventional 

1. Nuclear-powered submarines (SSNs & SSBNs) 

• Virtually unlimited endurance 
• Higher speed, deeper diving capability 
• Strategic roles (especially SSBNs with nuclear missiles) 

China dominates here. India is building capability. Pakistan has none. 

2. Diesel-electric submarines (SSKs) 

• Quieter at low speeds 
• Limited endurance (unless equipped with AIP) 

3. AIP (Air-Independent Propulsion): The Game-Changer 

• Allows subs to remain underwater for weeks 
• Crucial in littoral (coastal) warfare 

Pakistan currently has an edge in AIP deployment timelines, while India is in the process of integrating the technology through its next-generation submarine programs. 

Strategic doctrines: Three different approaches 

China: Blue-Water Dominance 

China’s submarine fleet supports: 

• Global power projection 
• Sea lane control 
• Nuclear deterrence 

Its shift to nuclear submarines reflects ambitions far beyond regional waters. 

Pakistan: Sea Denial 

Pakistan’s doctrine is defensive but potent: 

• Target Indian ships near its coast 
• Use stealth submarines to offset India’s larger navy 
• Focus on chokepoints in the Arabian Sea 

India: Hybrid Strategy 

India sits between the two: 

• SSBNs for credible nuclear deterrence 
• Conventional fleet for regional dominance 
• Future SSNs planned for offensive capability 

The real question: What happens in a two-front war? 

Against Pakistan 

India has a clear edge: 

1. Larger fleet 
2. Nuclear-powered submarines (Pakistan has none) 
3. Greater operational depth across multiple naval bases 

Verdict: India dominates in a bilateral naval conflict. 

Against China 

This is where the balance shifts significantly: 

China’s advantages: 

1. Much larger submarine fleet 
2. Strong SSN presence 
3. Expanding Indian Ocean deployments 

India’s advantages: 

1. Geographic proximity (home waters) 
2. Familiarity with Indian Ocean chokepoints 
3. SSBN-based nuclear deterrence 

Verdict: China holds numerical and technological superiority, particularly in nuclear attack submarines. 

Two-Front Reality (China + Pakistan) 

This is India’s most complex scenario. 

Key pressure points: 

• Arabian Sea: Pakistan’s AIP submarines create localised threats 
• Indian Ocean: Chinese SSNs extend operational reach 
• Resource split: India must divide its submarine fleet across two fronts 

Hidden weakness: India’s capability gap 

Despite progress, India faces structural challenges: 

• Ageing conventional fleet, with several submarines over three decades old 
• Delays in AIP integration 
• Lack of an operational indigenous SSN fleet 
• Slower production pace compared to China 

Numbers alone are no longer enough — stealth, endurance, and sensor superiority are now the defining metrics of submarine power. 

Future battlefield beneath the waves 

The character of naval warfare is undergoing a quiet but profound shift. Surface warships, once seen as the primary instruments of maritime power, are increasingly vulnerable to long-range missiles and surveillance systems. In contrast, submarines — especially those that can remain submerged for extended durations — are emerging as the most survivable and strategically decisive assets. 

For India, the coming decade will be crucial. The success of programmes aimed at building next-generation conventional submarines with AIP, along with the long-delayed push to develop indigenous nuclear attack submarines, will determine whether it can narrow the gap with China. At the same time, maintaining a credible sea-based nuclear deterrent through its SSBN fleet will remain central to its strategic doctrine. 

China, meanwhile, is expected to accelerate its transition toward a predominantly nuclear-powered fleet. This would give it the ability to sustain long-duration deployments in the Indian Ocean, challenging India not just near its coastline but across a wider maritime theatre. Pakistan, though smaller in scale, will continue to sharpen its asymmetric capabilities, relying on stealth and surprise to complicate India’s naval calculations in the Arabian Sea.