Asia’s Strongest Submarine Fleets in 2026: China Leads, North Korea Outnumbers Japan

The submarine is the most expensive and hardest-won class in modern naval warfare. A frigate can be bought and put to sea in a few years; sustaining a submarine force takes decades of investment in yards, training, maintenance and sonar infrastructure.

Using Global Firepower’s 2026 dataset, we ranked Asia’s ten largest submarine forces. Non-regional Pacific powers – the United States, Russia and Australia – are excluded, so this table shows the balance among Asian states themselves.

We start at tenth and work up. Read to the end for why hull counts say so little, which country fields more boats than a rival spending twelve times as much, and where Turkiye would rank if it were included.

Taiwan closes the list with four submarines – the product of one of the hardest procurement equations anywhere. No major shipyard will sell submarines to Taipei without risking its commercial relationship with Beijing.

Two of the current boats are Dutch-built Zwaardvis-class vessels acquired in the 1980s. The other two date from the Second World War and serve only for training. In practice, Taiwan has two combat-capable submarines.

To break the deadlock, Taipei started building its own. Hai Kun (Narwhal), designed and integrated domestically, was launched in 2023 and remains in acceptance trials. The programme targets eight boats. If it succeeds, it closes the single largest gap in the island’s defence doctrine.

The stakes go well beyond fleet size. In any amphibious scenario, Taiwan must be able to threaten the other side’s sea lines of communication, and the submarine is the only platform that can do it. Backed by 91 warships and 258 combat aircraft, the island’s asymmetric deterrence rests heavily on this programme.

For scale: Taiwan’s $31.18 billion defence budget is triple Indonesia’s, yet the two are level on submarines.

Ninth place: the world’s largest archipelago – with an undersea fleet out of all proportion to its geography.

Indonesia takes ninth with four submarines. For a nation of more than 17,000 islands commanding three major straits – Malacca, Sunda and Lombok – that is a strikingly thin force.

The backbone is the South Korean-built Nagapasa class, a Type 209 derivative, one of which was assembled at Indonesia’s PAL shipyard, giving the country a first foothold in submarine construction. The loss of KRI Nanggala in 2021 sharpened debate over both fleet size and sustainment standards.

Jakarta signed for Scorpene Evolved boats from France to close the gap, with part of the work planned for domestic yards. The medium-term goal is a double-digit fleet.

Indonesia’s naval strength actually lies on the surface: 338 warships make it one of Asia’s most numerous fleets, though largely patrol and landing craft. The country also works closely with Turkish industry, with cooperation in uncrewed aircraft and armoured vehicles expanding in recent years.

For scale: Indonesia’s 338 warships make it Asia’s second most numerous fleet after China – yet it trails Singapore under water.

Eighth place goes to a city-state smaller than most Asian provinces.

Singapore is eighth with six submarines. That a 730-square-kilometre city-state outranks countries hundreds of times its size is one of the more telling details on this list.

The new backbone is the German-built Invincible class (Type 218SG). Fitted with air-independent propulsion, these boats were specifically tailored for the shallow, congested waters of the Malacca Strait – a textbook case of adapting an export design to a customer’s operating environment.

Singapore’s approach is known as the ‘poisoned shrimp’ doctrine: be small, but expensive to swallow. Its $18 billion budget is the highest in Southeast Asia and among the highest in Asia as a share of GDP.

Behind 51,000 regulars sit conscription and a deep reserve pool. With 100 combat aircraft and 101 warships, Singapore fields one of Asia’s densest armed forces relative to population.

For scale: Singapore spends roughly twice what Vietnam does on defence, and the two are level on submarines.

Seventh place built its fleet around a single strategic calculation: the South China Sea.

Vietnam is seventh with six submarines – all Russian-built Kilo-class (Project 636) boats, and collectively the country’s largest single defence investment of the past two decades.

Hanoi’s calculation is straightforward. Facing competing claims in the South China Sea and a rapidly growing Chinese navy, it chose undersea deterrence over surface competition. Armed with Klub cruise missiles, those Kilos extend that deterrence hundreds of kilometres from the coast.

The wider force remains land-heavy: 1,999 tanks and 450,000 active personnel. The air force fields 61 combat aircraft in an ageing fleet, and Hanoi has been shopping for a next-generation type for years.

Procurement policy is shifting too. Long almost entirely Russian-sourced, Vietnam’s inventory is now being deliberately diversified, with Turkish, Indian, Israeli and Korean products under close review – including contacts with Turkiye on uncrewed aircraft and naval systems.

For scale: Vietnam spends more than Pakistan on defence, yet fields three-quarters as many submarines.

Sixth place has made its submarine force part of its nuclear deterrent.

Pakistan is sixth with eight submarines – French-built Agosta 90B (Khalid class) boats plus older Agosta 70s. The real transformation, however, is arriving from China.

Islamabad ordered eight Hangor-class boats, derived from the Type 039B, with half built in China and half at Karachi. Once delivered, Pakistan’s submarine force will double in size and gain air-independent propulsion, sharply extending submerged endurance.

The undersea arm sits at the centre of Pakistan’s second-strike debate. Test launches of the Babur-3 cruise missile from a submarine are widely read as a counterweight to India’s nuclear submarine programme.

The Turkish connection is a chapter of its own. The Babur-class (Jinnah-class) ships are an evolved Ada-class design built partly in Karachi, and Turkish industry carried out the modernisation of Pakistan’s Agosta 90B submarines – Turkiye’s largest reference in submarine modernisation exports.

For scale: Pakistan spends less than a tenth of what India does, yet fields nearly half as many submarines.

Fifth place is one of only two Asian countries operating ballistic missile submarines.

India is fifth with 18 submarines and, alongside China, one of only two countries on this list operating nuclear-powered boats.

The fleet has three layers. First, Kalvari-class boats built to the French Scorpene design at Mazagon Dock in Mumbai. Second, Russian-origin Kilo-class (Sindhughosh) submarines. Third, and strategically most significant, the wholly indigenous Arihant-class ballistic missile submarines.

The Arihants form the sea leg of India’s nuclear triad. Armed with K-15 and K-4 ballistic missiles, they give New Delhi a survivable second-strike capability – something only two Asian states possess.

With 343 warships, 2,183 aircraft and 1.43 million active personnel, India ranks 4th worldwide in Global Firepower’s 2026 index, and its $109 billion budget makes it Asia’s second-largest spender. The long-term goal is a 24-boat force capable of sustaining sea control across the Indian Ocean.

For scale: India fields more than twice Pakistan’s submarines – on twelve times the defence budget.

Fourth place designs, builds and now exports its own submarines.

South Korea is fourth with 22 submarines, all built in its own yards. The country ranks 5th worldwide in Global Firepower’s 2026 index.

The trajectory is remarkable. Seoul began with licensed Type 209 construction in the 1990s, moved to the Type 214, and ultimately produced the fully indigenous KSS-III (Dosan Ahn Changho class) – one of very few non-nuclear designs with vertical launch cells for ballistic missiles.

That capability is now an export line. Hanwha Ocean and HD Hyundai compete in submarine tenders from Poland to Canada, and the country has become one of the world’s fastest-growing defence exporters on the back of the K2 tank, K9 howitzer and FA-50 aircraft.

The strategic driver sits to the north. Pyongyang’s efforts to field a ballistic missile submarine push Seoul to invest in both anti-submarine warfare and its own undersea strike. An inventory of 827 helicopters – among Asia’s largest rotary fleets – reflects the same high state of readiness.

For scale: South Korea comes within one boat of Japan’s fleet on three-quarters of Japan’s budget.

Third place operates what are widely rated the quietest conventional submarines in service.

Japan is third with 23 submarines, every one domestically designed and built. The Soryu and Taigei classes are considered among the most advanced conventional boats in service anywhere.

Japanese undersea doctrine rests on two principles: silence and endurance. The later Soryus and the entire Taigei class were the first series-production submarines to replace lead-acid cells with lithium-ion batteries, markedly extending submerged endurance and quiet running.

The fleet is also renewed on a strict cycle. Japan retires boats after a relatively short service life and replaces them, which keeps a continuous production line running at the Kawasaki and Mitsubishi yards.

Geography explains the rationale. Japan is an island chain sitting directly astride the passages through which China’s navy reaches the Pacific. Backed by 583 helicopters, 1,429 aircraft and 158 warships, the submarine force is configured to monitor – and if required, close – those gaps. At $58 billion, its defence budget is Asia’s third largest.

For scale: Japan outspends South Korea by 30 percent, but leads it by a single submarine.

Second place has the largest fleet on this list by hull count – and the oldest by design.

North Korea takes second with 24 submarines – the most anomalous entry here. On a $4.75 billion defence budget, roughly eight percent of Japan’s, it fields more hulls than Japan.

This is also where the gap between numbers and capability is widest. Most of the fleet consists of Romeo-class derivatives built on 1950s technology: noisy, short-legged and vulnerable to modern anti-submarine warfare.

Doctrine uses them differently, however – coastal mining, special forces infiltration and threatening regional shipping through sheer numbers. Small Sang-O and Yono midget submarines belong to the same asymmetric line of effort.

The significant development is on the missile side. Pyongyang has conducted submarine-launched ballistic missile tests and unveiled a converted Romeo-class boat as a missile carrier. For a country already fielding 4,895 tanks and 1.32 million active personnel, undersea missile capability is the newest leg of its deterrence equation.

For scale: North Korea operates one more submarine than Japan on one-twelfth of Japan’s defence budget.

The fleet at the top nearly matches the other nine countries on this list combined.

China operates 61 submarines – one of the largest undersea forces in the world, and close to the combined total of the other nine countries on this list. It ranks 3rd worldwide in the 2026 index.

The fleet has four layers. Conventional Yuan-class (Type 039A/B) boats carry air-independent propulsion. Shang-class (Type 093) nuclear attack submarines operate in open water. Jin-class (Type 094) ballistic missile submarines, armed with JL-2 and JL-3 missiles, form the sea leg of China’s nuclear triad. Older Ming and Song-class boats remain in coastal service.

What sustains all of this is shipbuilding capacity. China has the world’s largest shipbuilding industry, with commercial yards working alongside military production – an advantage in replacement and expansion rates that no regional state comes close to matching.

With 841 warships, 3,529 aircraft, 5,870 tanks and 2.03 million active personnel, China leads Asia in every category, and its $303 billion budget exceeds the combined total of the other nine countries here. The submarine force’s core strategic function is to sustain an access-denial belt reaching to the second island chain in the Western Pacific.

For scale: China’s submarine force outnumbers those of Japan and South Korea combined.

The verdict: does hull count or technology decide Asia’s undersea balance?

Few tables illustrate the limits of raw numbers as clearly as this one. North Korea sits second with 24 boats; Japan third with 23. One hull separates them. Twelve-fold spending separates them.

The real difference is inside the hull. Japan’s Taigei class, with lithium-ion batteries and weeks of submerged endurance, ranks among the quietest conventional submarines ever built. Most of North Korea’s fleet consists of Romeo-class derivatives that are comparatively easy to detect in a modern anti-submarine environment. Two adjacent numbers, two entirely different capabilities.

The second dividing line is shipbuilding. Four countries here can design and build their own submarines: China, Japan, South Korea and India. All four can expand without third-party approval. Taiwan is pursuing the Hai Kun programme precisely because political constraints leave it no seller. Indonesia and Pakistan are building capacity through licensed construction.

The third and most consequential division is nuclear. Only two Asian states operate ballistic missile submarines: China (Jin class) and India (Arihant class). Those boats provide a survivable second strike and shape regional deterrence more than any other line item. North Korea is pushing at that door; Pakistan is seeking a comparable balance through submarine-launched cruise missiles.

China’s 61-boat force belongs in its own category. Beijing’s advantage is not simply numbers but the world’s largest shipbuilding base, with commercial infrastructure feeding military production – an expansion rate no regional state can match. Against that, Chinese boats are still generally assessed as trailing Japanese and American submarines on acoustic signature and anti-submarine warfare proficiency.

Were Turkiye included, its 14 boats would rank sixth. The arrival of the Reis class and progress on MILDEN place the Turkish Navy among the small group of states holding the full design-build-modernise chain – and having modernised Pakistan’s submarines shows that competence converting into exports.

Asia’s largest submarine fleets: comparison table

Frequently Asked Questions

Sources

• Global Firepower 2026 Asia-Pacific regional listing and country profiles
• Official navy statements from the countries covered
• SIPRI Military Expenditure Database
• IISS The Military Balance
• Source: https://www.globalfirepower.com/