Can Taiwan's First Homegrown Submarine Change the Game Against China?

Can one submarine alter the balance of power in one of the world's most volatile waterways? Taiwan's first indigenously built submarine, the Hai Kun, has been conducting shallow-water dive tests over the past two weeks, marking a crucial milestone in the island's quest for naval deterrence against Beijing.

Two Decades in the Making

The Hai Kun – meaning "Sea Whale" – represents the centerpiece of Taiwan's Indigenous Defense Submarine (IDS) program, designed to boost asymmetric naval capabilities as Chinese military pressure intensifies. But the path to the water hasn't been smooth.

Originally scheduled for navy delivery in November 2025, the submarine missed its deadline after undersea trials and weapons testing fell behind. The delay prompted opposition lawmakers to freeze NT$1.8 billion ($56 million) in funding for follow-on submarines – part of a broader NT$284 billion program to build seven additional subs.

Facing mounting political pressure, manufacturer CSBC Corp conducted the first submerged test on January 29, followed by three more shallow-water trials. The company released its first official video of all four tests on Sunday, offering a glimpse of Taiwan's naval ambitions beneath the waves.

David's Slingshot Strategy

The submarine program reflects Taiwan's broader strategic reality: outgunned but not outmaneuvered. With China's navy boasting over 70 submarines compared to Taiwan's aging fleet of four (two 1980s-era Dutch boats and two 1940s-era American vessels), the island has turned to asymmetric warfare as its lifeline.

Submarines offer what surface ships cannot: stealth and surprise. In a potential conflict scenario, even a small submarine force could complicate Chinese naval operations, forcing Beijing to allocate significant resources to anti-submarine warfare. It's the maritime equivalent of guerrilla tactics – using mobility and concealment to offset numerical disadvantage.

Yet questions remain about effectiveness. Military analysts note that eight submarines (including the existing two and six planned new boats) may still be insufficient to meaningfully deter a Chinese invasion. The math is sobering: China's submarine fleet outnumbers Taiwan's planned force by nearly 10 to 1.

The Technology Tightrope

Taiwan's submarine program highlights the complexities of defense independence in an interconnected world. While marketed as "indigenous," the Hai Kun relies heavily on foreign components, from sonar systems to torpedoes sourced from the US and Europe.

This dependency creates both opportunities and vulnerabilities. Foreign partnerships provide access to cutting-edge technology that Taiwan couldn't develop alone. But they also create potential chokepoints if suppliers face Chinese pressure or changing political winds.

The submarine's development has taken over 20 years, partly due to Beijing's diplomatic pressure on potential partners. Even now, Taiwan struggles to find suppliers willing to risk Chinese retaliation for key submarine technologies.

Beyond the Waves

The Hai Kun's significance extends beyond military capabilities. For Taiwan's 23 million people, the submarine represents technological achievement and national determination. It's a symbol that Taiwan can still chart its own course despite Chinese pressure.

For Beijing, however, the submarine likely reinforces perceptions of Taiwan as a "separatist" threat requiring stronger countermeasures. Each technological milestone may paradoxically increase rather than decrease tensions.

For Washington, Taiwan's submarine program presents both opportunity and risk. Supporting Taiwan's defense capabilities aligns with US strategic interests, but each advancement raises the stakes in an already volatile relationship with China.