Note: This concepts-themed post engages in inherently somewhat speculative analysis. I contend that any serious analysis must engage with the world both as it is and as it can be. Avoiding mindless empiricism requires cognizance of what is and what is not within the realm of possibility. Concepts-themed posts engage in this type of analysis.
In several recent posts, I have discussed how the People’s Liberation Army can use fixed-wing loitering strike drones, armed multirotor drones, and other types of guided munitions more generally to attack terrestrial targets on the island of Taiwan. This generally requires the use of a forward launch platform, such as an uncrewed aerial vehicle (UAV), uncrewed surface vehicle (USV), or even an uncrewed underwater vehicle (UUV), that can bring the aforementioned munitions within range of Taiwan.
In the second of the above posts, I explained that while UUVs can, in principle, be used to bring strike munitions, including armed uncrewed aircraft of both the multirotor and fixed-wing varieties, within range of Taiwan, USVs and uncrewed aircraft amount to a more straightforward way of doing so. All things considered, the PLA may be able to forgo using UUVs for such purposes in and around the Taiwan Strait. The PLA can, however, productively use UUVs to attack targets located along Taiwan’s eastern coastline, including the Taitung and Hualien areas. While the use of UUVs as ISR assets and (naval) mine laying systems has received a lot of attention in recent years, there is one potential application of UUVs in a cross-strait conflict that has received little attention to date: the PLA may use UUVs as submersible launchers for smaller, lighter, and shorter-range guided artillery rockets, among other strike munitions, than what it otherwise must use to attack targets on Taiwan from launch positions along the Fujian coastline.
Much of Taiwan’s western coastal plain has a width of just 25-35 kilometers. Even if one were to assume a launch position in the Taiwan Strait located around 25 kilometers from the Taiwanese coast, the PLA will only need a guided artillery rocket with a maximum range of around 60 kilometers. While something in the vein of the American 227 mm diameter M30/M31 GMLRS rocket design—the PLA is not understood to have a medium caliber artillery rocket system in its arsenal, although Chinese industry does offer such artillery rockets to export customers—is an option, these are quite large and heavy and therefore require a quite large UUV that can accommodate a pod of rockets and a launching mechanism. A much smaller and shorter-range guided artillery rocket, perhaps something in the vein of the 107 mm diameter Type 63 artillery rockets that have long been part of the PLA arsenal, is an option. Such artillery rockets exist in versions that weigh ~20 kilograms, are ~80 centimeters in length, and have a maximum range of 11 kilometers when equipped with a ~8 kilogram warhead.
Chinese industry notably offers such 107 mm artillery rockets in a version that comes with a semi-active laser homing (SALH) seeker. While typically reserved for larger, heavier, and longer-range guided artillery rockets, a INS+GNSS guided version is also an option. It is worth noting that a short time-to-target SALH 107 mm guided artillery rocket may make for a very useful means of delivering close fire support to PLA forces that land on the island of Taiwan, including PLA special operations forces and PLA heliborne air assault infantry.
It bears emphasis that using such rockets will typically require a UUV to surface in order to launch. Given this and the short distances that such an (reusable) armed Chinese UUV will need to cover in the Taiwan Strait, which is only some 130-180 kilometers wide at its narrowest points, the PLA may be better off using a submersible USV, as opposed to a true UUV, that will primarily operate on the surface and do so as a higher average speed.
Many other possibilities exist when it comes to UUV armament, not least if a UUV, or a submersible USV, will surface to launch the munitions it carries. Another option available to the PLA entails the development of a submerged-launch fixed-wing strike drone/loitering strike drone or a submerged-launch surface-to-surface missile/anti-tank guided missile, including perhaps designs of the fiber-optic cable communication uplink/downlink variety. While military and industry representatives have discussed such munitions over the years, there is little in the way of publicly available imagery. In early 2025, Iran did, however, informally unveil what appears to be an encapsulated submerged-launched propeller-driven fixed-wing strike drone/loitering strike that is seemingly intended for use with submarines and perhaps UUVs. Such a munition, which is far more practical as a fire-and-forget strike drone as opposed to a human-in-the-loop loitering strike drone—a more complex and more expensive fully autonomous loitering strike drone is, however, a possibility—constitutes a template for what a non-artillery rocket land attack armament for a non-surfacing land-attack UUV may look like.
UUV technology is undergoing an ongoing growth spurt that is driven not only by advances in automation technology but also by improvements in the specific energy and energy density of electric batteries in general and low-cost, commercial-off-the-shelf batteries in particular. Battery technology and battery production are notably areas in which China is internationally dominant. As things stand and notwithstanding ongoing improvements, UUVs tend to be limited in terms of speed-range, range-endurance, and range-payload. The Taiwan Strait is, however, quite small, and an operational concept that entails the use of UUVs, or perhaps submersible USVs—that will likely be powered by electric batteries while submerged—that only submerges when approaching the Taiwanese coastline, after navigating from starting locations along the Fujian coastline—is no less feasible than the use of much the same UUVs as (naval) mine layers over comparable distances. It is worth noting that China displayed two quite large UUV designs at the 3 September 2025 military parade in Beijing. The AJX002 design (left) appears to be a (naval) mine laying UUV.
Taiwan’s anti-submarine warfare capabilities are likely to be very limited in wartime, it seems doubtful that any American nuclear-powered attack submarines in the Taiwan Strait would to expend a precious torpedo, even a sub-caliber lightweight torpedo with a diameter of less than 533 mm, to hunt all but the largest of Chinese UUVs, not least if China employs UUVs in large numbers. Whereas Taiwan’s air defences and coastal defences have decent prospects when it comes to detecting and shooting down/sinking PLA fixed-wing “mothership” drones and similar and PLA USVs approaching the Taiwanese coastline, an armed land-attack UUV and/or an armed land-attack submersible USV will not only be more difficult to detect but also more difficult to damage or destroy. While the PLA has many options available to attack targets along Taiwan’s western coastline, larger and longer-range land-attack UUVs can be used to attack targets located along Taiwan’s eastern coastline, including the Taitung and Hualien areas. Larger and longer-range UUVs will, of course, be more expensive and will, therefore, likely be available in more limited numbers.
In this post, I set out to highlight one area in which technological change is dramatically expanding China’s options when it comes to attacking terrestrial targets on the island of Taiwan. It goes without saying that the PLA and Chinese decision-makers are unlikely to prioritize such a rather slow approach to attacking targets on the island of Taiwan. Given the stakes involved, the PLA is likely to allocate far more effectual, faster, and longer-range munitions to attack terrestrial targets on the island of Taiwan, at least for as long as such munitions are available in the requisite very large numbers. There, are, however, scenarios in which an armed land-attack UUV is likely to be more appealing. One such scenario concerns how the PLA may prosecute a protracted war in which a PLA amphibious landing attempt either fails or is indefinitely postponed as a result of a decisive American military intervention that fundamentally reshapes the wartime cross-strait military balance. In any event, it is important for observers to be mindful of what is and is not within the realm of possibility as it concerns Chinese military capabilities in what is likely to be an extremely high intensity protracted conflict to determine the fate of Taiwan.