Taiwan launched its first indigenously designed and built submarine in September 2023. The vessel — named Hai Kun, or Narwhal — represented the culmination of a program that was announced in 2016, funded against significant domestic political opposition, and executed despite the near-total unavailability of normal defense industrial cooperation channels. No major submarine-building nation would sell Taiwan a complete submarine. The United States, which provides most of Taiwan’s conventional weapons, does not export submarines to any partner. Taiwan built one anyway, with foreign assistance obtained through channels that required deliberate diplomatic ambiguity from the governments whose citizens and companies were involved.

Taiwan cannot always buy what it needs. Major defense suppliers limit what they will sell to avoid diplomatic friction with China. American export control legislation restricts the transfer of sensitive technologies. Treaty allies of China will not sell Taiwan weapons at all. The result of these constraints, accumulated over decades, is that Taiwan has been forced to develop a domestic defense industrial base capable of producing the systems it cannot obtain externally — and in several categories, the systems it has developed domestically are among the most important in its order of battle.