By: Benjamin Tkach and Vasabjit Banerjee
There is a global shortage of submarines. The United States, the world’s largest arms exporter, does not export its nuclear-powered submarines, although the AUKUS arrangement with Australia will enable Australia to operate American Virginia-class attack submarines before receiving new U.S.-developed vessels. At the same time, U.S. domestic production is behind its own production rates. AUKUS could further exacerbate production problems, potentially leaving Australia scrambling for submarines if the program falters.
The picture is little different elsewhere. Global submarine construction is concentrated in France, Germany, Russia, China, and Sweden. Meanwhile, Turkey and India are pursuing their own programs and Spain, South Korea, and Taiwan are delivering submarines domestically. Delays in French designs were part of Australia’s justification for terminating its naval group contract and formalizing AUKUS with the United States and United Kingdom. Meanwhile, Russia announced the new Yasen-M-class missile boat, which will strain its already overtaxed industrial base. Across manufacturers, common contributing factors to submarine production delays include design delays, skilled labor shortages, supply chain entanglements, and shifting national priorities.
Yet submarines remain essential for the national security strategies of several maritime powers. Currently, both India and Taiwan need far more submarines than they currently possess to deter China in the Pacific and Indian Oceans. For Taiwan, submarines offer undersea capabilities not provided by other military means: stealth sea denial and anti-access delivery of anti-ship capabilities against Chinese ship movements. For India, submarines are likewise central to sea denial strategies and establishing a credible second-strike nuclear deterrent.
At present, both India and Taiwan are reliant on others to provide submarine hulls and major subsystems. These initial phases of defense industrial development are essential to fostering domestic defense production capacity that simply importing or reverse engineering capabilities cannot achieve, offering complementary areas of potential collaboration. India and Taiwan are unlikely to sign formal defense cooperation agreements at a government-to-government level because of the lack of formal diplomatic recognition. But consistent with other areas of economic engagement, both actors can leverage industrial and technological agreements between private entities to pursue cooperative gains.
Air Independent Propulsion and Lithium-Ion Batteries
Cooperation between India and Taiwan may at first glance seem far-fetched. But complementarities exist between India’s aim to acquire Air Independent Propulsion (AIP) and Taiwan’s expertise in lithium-battery technology. Diesel-electric submarines operate using batteries and — unlike nuclear submarines — must surface or snorkel every few days to recharge. AIP systems provide an alternative power source while submerged, avoiding the need for atmospheric oxygen through snorkeling or surfacing. Lithium-ion batteries also enhance the capabilities of AIP systems. Japan's Ōryū, launched in 2020, was the first submarine to fully adopt lithium-ion batteries.
India intends to equip its submarines with AIP systems that rely on French technology. The second batch of India’s Kalvari-class submarines — an indigenously produced version of the French Naval Group’s Scorpène Evolved — will include AIP systems. India’s AIP system is distinctive for using phosphoric acid fuel cells, though the technology remains unproven. If India cannot bring this technology to maturity, it will need support from partner nations to advance its AIP program. For India, Taiwan’s advanced lithium-ion manufacturing sector presents an opportunity to form technical partnerships that support both nations' submarine development goals.
Taiwan is a leader in lithium-ion battery technology and closed-loop recycling systems. Industrial scaling of Taiwan’s innovative battery technology is necessary for these battery systems to be integrated into submarines. Critically, Taiwanese companies have established the first closed-loop recycling ecosystem for lithium-ion batteries. This system enables the recycling and recovery of rare earth metals, lithium, and other essential materials for creating new cathode materials. Closed-loop systems hold significant potential for both Taiwan and India because they can reduce reliance on Chinese-controlled lithium production and refinement by creating alternative supply chains.
Taiwan’s submarine program will also benefit from collaborations with India. Taiwan mainly operates a value arms submarine fleet consisting of refurbished submarines like the Guppy-class and legacy technologies in the Zwaardvis-class. India faces a similar challenge with its diesel-electric 1980s submarines, of which seven are Soviet-origin Kilo-class and four are German Type-209 submarines. Personnel and workforce constraints offer another area of potential collaboration. It has been reported, for example, that former engineers involved in the construction of India’s Kalvari-class submarine have been hired for training and other functions in Taiwan.
Political and Legal Barriers
Legal and political barriers to such cooperation exist but are surmountable. Despite its lack of formal diplomatic recognition, several countries cooperate with Taiwan in the coproduction of submarines, such as the Haikun-class diesel electric submarine. There are also potential export control constraints. Diesel, electric, and AIP engines are listed under India’s legal regime governing the export of weapons and related technologies (the Special Chemicals, Organisms, Materials, Equipment and Technologies list under the Foreign Trade Act or SCOMET), but neither the export of submarine propulsion data and designs nor hull-related data and designs are mentioned in the list. Although the list of states for which SCOMET rules were relaxed for dual-use technologies in 2024 did not include Taiwan, collaboration with Taiwan on dual use technology is being discussed in India. Overall, India and Taiwan have shown resilience in deepening ties where mutual strategic interests align.
Submarine production difficulties affect the global marketplace and place a premium on domestic production. India’s pursuit of untested technologies elevates its risk, while Taiwan’s domestically produced system relies on foreign components. Both, therefore, have a lot to benefit from engineering and design cooperation in submarine production.
Benjamin Tkach is Associate Professor of Political Science at Mississippi State University and Vasabjit Banerjee is Assistant Professor of Political Science at the University of Tennessee, Knoxville.