Taiwan’s stealth submarine push rocked by technical turbulence

Taiwan’s flagship submarine project, the Hai Kun (Narwhal), missed a key sea trial deadline— leaving a multibillion-dollar stealth gamble potentially dead in the water.

This month, the South China Morning Post (SCMP) reported that Taiwan’s ambitious Indigenous Defense Submarine (IDS) program encountered a significant setback in September, raising doubts about whether the vessel can be delivered to the Navy by November.

Defense Minister Wellington Koo Li-hsiung said meeting the target would be “quite challenging” after repeated technical setbacks since surface tests began in June.

The submarine spent weeks in dry dock following its third sea trial in July, signaling possible “structural or key technical challenges,” according to retired Navy captain Huang Cheng-hui, who cited suspected leaks in the main engine’s cooling system that may require extensive disassembly.

The project’s integration of systems sourced from multiple countries—forced by China’s diplomatic pressure against arming the self-governing island—has compounded difficulties, with US defense contractor Lockheed Martin struggling to synchronize sonar, mast and combat components described critically by one official as a “United Nations of systems.”

Lawmakers have frozen NT$1.8 billion (US$56 million) in funding for seven planned follow-on submarines until the Hai Kun passes trials. Analysts warn that prolonged delays could undermine Taiwan’s asymmetric defense strategy against mounting Chinese military drills.

At the same time, critics question the decision to build eight submarines domestically despite limited local shipbuilding experience.

IDS program supporters argue that the submarines are a necessary asymmetric platform to offset China’s naval advantages, while detractors counter that it is a prestige program that diverts limited resources from more survivable and cost-effective military assets.

Submarines could enable Taiwan to ambush China’s much larger navy, break a blockade, prevent an amphibious landing and safeguard approaches to key ports for US and allied resupply and reinforcement in a crisis scenario.

However, they may be of limited value against China’s intensifying gray zone operations around Taiwan, as these ambiguous but visible intrusions may be undeterred by invisible stealth assets. To deter China’s gray zone incursions of ships and aircraft, Taiwan relies on high-profile assets such as fighter jets and frigates to provide a visible response.

However, these high-profile assets may not be survivable in the event of a Chinese invasion of Taiwan, as their visibility makes them vulnerable to being located, tracked and targeted. While submarines could survive for longer without timely US and allied support, they could eventually be located and destroyed by China’s anti-submarine warfare (ASW) capabilities.

Fighter jets, frigates and submarines could be looped together as a remnant of Taiwan’s “US syndrome,” stuck in a past when the US and Taiwan enjoyed military superiority, with the latter’s Kuomintang leadership still entertaining the fanciful idea of retaking mainland China from the ruling Communist Party.

That mentality may have led to Taiwan’s investment in high-end, high-profile, high-visibility assets that, while effective against a previously militarily inferior China, would be of limited effectiveness and doubtful survivability against China’s military today.

Critics say Taiwan’s submarine money would have been better spent on small, numerous and cost-effective assets that could ride out China’s initial strikes, are easily concealable, scalable for attrition warfare, and could bring home the costs of an invasion to Beijing.

Taiwan has been dovetailing in its military modernization, focusing on acquiring conventional assets such as fighter jets, frigates, submarines, heavy artillery and tanks, while also building a formidable asymmetric arsenal of long-range missiles, naval mines and drones.

Those asymmetric assets could anchor a “porcupine strategy”, a defensive posture designed to raise the costs of a Chinese invasion, or a “pit viper strategy”, one that allows for limited offensive strikes on mainland China.

China could counter a porcupine strategy by blockading Taiwan into submission, framing it as an “internal security operation,” starving the self-governing island of information, energy and food supplies while deterring US and allied intervention.

A possible blockade of Taiwan would mirror its “cabbage strategy” in the South China Sea by surrounding the island with concentric rings of Chinese Coast Guard (CCG) and People’s Liberation Army Navy (PLAN) ships, all under the strategic cover of the PLA Rocket Force (PLARF) and China’s nuclear arsenal.

But a blockade could be a low-risk, low-reward approach. Without PLA boots on the ground, high Taiwanese social cohesion, popular nationalist leadership and willingness to endure hardship – all spurred on by the hope of US and allied intervention – Taiwan is unlikely to go down without a fight.

China could also go all-in with an invasion of Taiwan, a high-risk but high-reward approach. In such a scenario, China could employ short and sharp decapitation air and missile strikes alongside pre-deployed special operations forces “kill teams” to swiftly neutralize Taiwan’s key military facilities, assets and leadership.

Should the decapitation operation succeed, China could then rush invasion forces over the Taiwan Strait to quickly seize the island before Taiwan’s remaining resistance and the US and allies could react.

But should the decapitation operation fail, Taiwan could implement a pit viper strategy, launching retaliatory long-range counterstrikes on staging areas, military bases, energy facilities and industrial centers to hobble China’s capacity to sustain an invasion and stir public opposition to the operation. Taiwan’s submarines, if armed with land-attack cruise missiles, could form the backbone of a conventional second strike capability.

However, those same strikes could provide the Chinese Communist Party (CCP) a strong argument to the Chinese public to rally around the flag and double down on an invasion of Taiwan, with those strikes achieving the opposite of what they were intended to in terms of influencing public opinion. Facing the full might of the PLA, Taiwan’s prospects dim considerably without US and allied fortifications.

Should those fail in turn, Taiwan could implement its take on a “poison shrimp” strategy, one that aims to make the island “indigestible” to Chinese occupation forces – mirroring the US experience in Vietnam and Afghanistan.

Should Taiwan’s organized resistance collapse, it could continue resisting via irregular forces and civil disobedience, increasing the cost of occupation to sap China’s political will to fight, while drawing in international support – and possibly buying time for outside assistance.

But unlike the Vietcong in Vietnam or the Taliban in Afghanistan, overland resupply is not an option for Taiwan, and it lacks access to cross-border safe havens, precluding a Fabian “winning by not losing” strategy.

Additionally, without US and allied intervention, China can increase counterinsurgency efforts to weaken and eliminate what remains of Taiwan’s resistance. It can also employ elite co-optation, its intelligence apparatus and heavy-handed tactics to discourage support for popular resistance.

Ultimately, Taiwan’s hopes for survival rest on the level of US commitment, and the quality of the democratic island’s political leadership, social cohesion, resilience and perhaps a set of military capabilities entirely different than what a few submarines could deliver.