On Wednesday morning, Chinese President Xi Jinping (習近平), Russian President Vladimir Putin and North Korean leader Kim Jong Un looked on as the People’s Liberation Army sent a parade of soldiers and military equipment past Tiananmen Square in Beijing. But the most menacing image may have been a new group of weapons that won’t always float.
Bracketing what a commentator for the state-owned China Global Television Network referred to as the PLA’s “unmanned maritime combat formation” were two new models of extra-large uncrewed underwater vehicles, or XLUUVs, cigar-shaped submarines roughly the length of an 18-wheeler. Out front were a pair of HSU100s, a two- to three-meter-thick model never before revealed to the public. At the rear were four AJX002s, whose slimmer body presented a more eel-like silhouette.
“They’ve obviously put a great deal of investment into this program, and it looks like they have some of the world’s leading technology and industrial capacity for uncrewed undersea vehicles,” said Isaac Kardon, a senior fellow for China studies at the Carnegie Endowment for International Peace.
The PLA’s navy is in the midst of an unprecedented buildup, with aspirations to not only intimidate Taiwan into submission but also challenge U.S. supremacy in the broader Pacific. Military analysts now believe that XLUUVs, a class of weaponry that barely existed a decade ago, will be crucial to both.
“We’re talking about, if not a revolution in naval warfare, then something approximating one,” said Lyle Goldstein, founder of the U.S. Naval War College’s China Maritime Studies Institute who now teaches at Brown University.
In August 2023, Ukraine crashed a sea drone into the hull of the 112-meter Olenegorsky Gornyak, a Russian military transport ship from its Northern Fleet. Unian news agency reported at the time that the uncrewed surface vessel was carrying 450 kilograms of explosives and had done enough damage to force the Gornyak out of commission. Since then, Ukraine has used sea drones to sink other Russia ships, challenging what was once its rival’s unquestioned dominance in the Black Sea.
In the Pacific, China is seeking to project power in a much different maritime environment, one defined by long distances, deep waters and strategic goals that demand stealth rather than speed. The large underwater drones are well-suited for such a domain, said Mark Montgomery, retired U.S. Navy rear admiral and senior fellow at the Foundation for Defense of Democracies. “These are pretty damn big. You could put a lot of fuel in them,” he said, adding: “You may or may not see it enter the water in a maritime base, and you don’t really know where it’s at. Ten hours later, it could be almost anywhere.”
The AJX002, the more slender of the two new XLUUVs, has drawn comparisons to Russia’s Poseidon system, an uncrewed, long range, nuclear-powered and nuclear-armed torpedo that it first announced in 2015. The Poseidon isn’t expected to go into service until 2027, but it has already generated breathless reports about 1,000-foot-tall radioactive tsunamis and devastated coastal cities. H. I. Sutton, who first reported the existence of the AJX002 two weeks ago, argued in an article for Naval News that comparisons with the Poseidon were unwarranted. “There are no clear indications that [the AJX002] is nuclear powered,” he wrote.
Even if they can’t launch an atomic tsunami, the new XLUUVs’ size will allow them to carry out a variety of operations that could menace Taiwan. They could conduct reconnaissance on Taiwanese submarine cables. They could shoot torpedoes at Taiwanese vessels. They could fire missiles from vertical attack tubes to strike targets on land.
In a 2024 report on the mechanics of a Chinese blockade of Taiwan, the Center for Strategic and International Studies found that covert mine-laying operations around Taiwanese ports would be crucial to China’s efforts to isolate the island. Brian Hart, deputy director of the China Power Project at CSIS and one of the authors of that report, told Domino Theory by email that China’s new XLUUVs could serve just that purpose.
But Hart also noted that what really sets XLUUVs apart from their smaller counterparts is the ability to carry out long-range missions. Their greatest impact may not be on efforts to capture Taiwan, but in helping to shift the balance of power in the Pacific Ocean. “For a long time, the United States has had a significant advantage in undersea warfare,” he said. “But as China’s capabilities advance, that is changing.”
On some measures of naval strength, like numbers of aircraft carriers or experience operating nuclear submarines, China has no hope of competing with the U.S., at least not any time soon. But that hasn’t stopped Beijing from investing heavily to gain an edge in a set of capabilities that could subtly shift the dynamic in a conflict. Goldstein said the XLUUV program is a quintessential example of that approach. “China has a tradition of developing asymmetric weapons, and I think this fits very well in that kind of tradition,” he said.
Misha Lu (呂亦塵), a research fellow at the Taipei-based think tank SciTech Power Research, agreed. “China will always try to compete with what you are not good at,” Lu said.
The U.S. has long been working to develop its own XLUUV capabilities. The Navy’s 2004 Unmanned Undersea Vehicle Master Plan called for the maintenance of “a balanced UUV technology program” that would include large submarine drones exceeding 20,000 lbs (roughly 9,000 kilograms). But progress has been slow, and the flagship Boeing Orca system, which the Navy ordered five of in 2019, has faced delivery delays. “We have not been solid on this,” Montgomery said.
Captain Matt Lewis, a program manager for the Navy’s Unmanned Maritime Systems office, said in an interview with the online defense industry publication The War Zone earlier this year that the U.S.’s shortcomings aren’t for lack of imagination. “It’s easy to think of things, but it’s not necessarily that easy to design them and build them,” he said.
Operating submarines is hard enough with people on board. The density of water makes it difficult to reach any significant speeds, and electromagnetic signals have to be sent at wavelengths so long that bandwidth can be as low as a few bits per second. In many cases, communications cease altogether.
“Underwater warfare is a little bit like being in space, because you’re absolutely cut off and shut off from the environment,” said Alex Luck, a freelance naval analyst based in Australia. “You have to have lots of capability in a design that needs to act by itself, or be controlled in a way that is very exotic.”
Most of the freshest intelligence on submarine technology remains classified, but having closely followed recent developments in XLUUVs, Montgomery suspects that the U.S. is falling behind China. “These are all unknowns right now,” he said. “However, my gut reaction is they’re probably moving faster than the United States … I’ve heard us talk about building dozens of XLUUVs over time. If we could do that, they can build hundreds.”
On Tuesday, in anticipation of the PLA parade, experts from the Taiwanese security community gathered at a conference hall in Taipei to discuss how Taiwan should respond to growing Chinese military threats. Chang Sheng-kai (張勝凱), principal of Taiwan’s Marine Corps School, who was invited to give a talk on countering PLA naval threats, called on Taiwan to accelerate construction of combat capabilities specifically targeting Chinese submarines. His presentation did not, however, touch on the novel menace of XLUUVs.
Goldstein thinks that, even in the best of circumstances, China’s new XLUUVs will be hard to counter. “It’s a very hard target,” he said. “I think Taiwan has its hands full, really, in all respects.”
Leave a Reply