Assessing Chinese Anti-Submarine Warfare Operations
“When the PLAN’s underwater quantum mapping network sensors picked up the American fleet a few days earlier, Southern Fleet HQ dispatched attack subs from Hainan carrying the PLAN’s new Piranha drones for a trap. As the American ships began to populate outside of Cam Ranh Bay, PLAN activity grew silent. It wasn’t until American orbital ISR reserves were flying over the 12th parallel that the trap was sprung.” “As Above, So Below”, EX SUPRA
There are few operations that require greater secrecy than those below the waves. Fast attack boats lurk in the Pacific’s depths in a cat and mouse game with the prey, while boomers carry the darkest no-fail mission in the US military: deterrence through guaranteed second-strike capability, all the while aircraft, ships, sensors, and satellites hunt to expose those down below. The elusiveness and lethality of submarines, and the efficiency and expertise with which American submariners manage their vessels, are exactly why the PLA cannot cross the Taiwan Strait until they are confident that they have reasonably mitigated the threat to their large, lumbering invasion fleet. The way some folks in the Fleet tell it, our subs are the ace up our sleeve in a Taiwan conflict. PLA missiles can bombard our bases and sink our surface fleet, but our subs will chew away at the PLA’s most important craft and break the invasion force from the murky depths of the Strait.
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From the US perspective, it’s hard to deny how good our submarine force is and how important our subs are to the larger war plan. But as longtime followers know, I’m a believer that anything can break with enough time, creativity, and violence. Nor do I believe the rapidly growing and modernizing PLAN submarine fleet to be a laughing matter. While the quality of green Chinese aircraft carrier crews and pilots might be up for debate, by all accounts Chinese submariners seem to be up to snuff. Our competitors can hold their own and we shouldn’t take for anything for granted. And when it comes to the war for Taiwan, if you can’t degrade and disrupt the amphibious landing force, it becomes very hard to prevent Taiwanese forces from becoming overwhelmed. This brings us to the topic of the day: PLA anti-submarine warfare operations, their impact on US operations, and potential methods of mitigation from policy to tactics.
First, let’s talk a little about the basics of US and Chinese submarines: US submarines are an entirely nuclear-powered force where the Chinese have a mix of conventional (diesel-powered) and nuclear submarines. At present, the Chinese are trying to rapidly build out their nuclear fleet in order to match ours. It’s important to understand, despite disinformation by anti-war protesters, that nuclear-powered doesn’t necessarily mean nuclear-armed. Nuclear-armed submarines (SSBNs) are part of the nuclear deterrent, are typically larger, and in the case of the US, can carry enough warheads to level the Chinese Eastern seaboard in a single salvo. At present, the US has 14 Ohio-class SSBNs at various states of readiness throughout the world. The other 52 nuclear-powered craft are a mix of Virginia, Seawolf, and Los Angeles-class attack vessels (SSNs). These fast-attack craft hunt other subs, surface vessels, conduct reconnaissance and surveillance missions, act as a screen and security for carrier groups, and support on-shore operations via land-attack cruise, and soon-to-be hypersonic, missiles. These SSNs will be at the forefront of disrupting any Chinese operations at sea.
For its part, the PLAN has a smaller number of boomers with fewer missile tubes than the US at 8 in service, with a compliment of 12 nuclear fast-attack vessels. However, the PLAN also operates some 58 non-nuclear attack craft. To break it down, the US nuclear-powered SSBN and SSN component is far superior in quality, quantity, and raw firepower to their Chinese counterparts. The Chinese have attempted to make up for this with rapidly produced diesel-powered fast attack craft. Diesel craft can sometimes be quieter than nuclear craft and therefore harder to detect, but their conventional propulsion also means they cannot operate without having to refit or return to port nearly as long as nuclear-powered craft. In terms of long-term operations, the US has the clear advantage. One more reason the PLA wants the war to go quick.
The above conventional offset is comparable to the development of the larger Chinese fleet, where their numbers and shipbuilding capacity have attempted to offset the numerically fewer but technologically superior and better-armed American equivalents. Above and below the waves, China is closing the quality gap and in some cases on the surface may surpass US capability. For the time being, 1 for 1, the US submarine fleet remains superior. But, the First Island Chain which includes Taiwan and is where most of the fighting will take place, are China’s local waters. By pure numbers and geography, they can “flood the zone” with submarines, leaving US subs to expend munitions and time hunting down Chinese subs to protect the Pacific Fleet and ensure their own survival as they hunt around the waters of Taiwan. For the sake of planning, let’s assume US subs, along with US and Japanese ASW capabilities, manage to keep PLA subs locked up in port or at the fringes of the conflict, could PLA ASW operations do the same to US subs where it matters most: in the Taiwan Strait?
For my soldiers, submarines are like snipers in terms of their impact on momentum on the battlefield. A single well-placed, skilled sniper can halt a whole infantry company in its tracks through fear and precision. Your commander goes down and you don’t know where the shot came from, everyone takes cover until they can get a better read on the situation. Under the waves, your capital ship or even a large transport vessel goes down and you don’t quickly find and sink the culprit, your risk calculus goes way up and many will become averse…or they’ll double down and die from doing something stupid. In a congested space like the Taiwan Strait, it’s an incredibly hostile but also target rich environment for American attack boats. Play your cards right and you’re a force multiplier that can strike fear in the hearts of every PLAN sailor. In an ideal world, your worst problem (and a very real one), is running out of ammo before you can break the invasion force and having nowhere nearby to reload.
In terms of geography, the short distance between Taiwan and the Chinese mainland means the PLA can run airborne anti-submarine operations quite frequently. In fact, the ADIZ intrusions around Taiwan by the PLAAF frequently include ASW exercises and aircraft. The PLA not only wants to become familiar with its hunting grounds from the air, it wants ASW operations to be almost reflexive for its maritime patrol crews. If the PLA can’t keep US submarines out of its own local waters, how can it beat expected to enforce a blockade around Taiwan or project power into the Western Pacific. The typically stormy waters and fluctuating around Taiwan are incredibly hazardous for littoral operations and air operations, depending on the time of year. The PLA may call those waters home, but the climate is hardly the friendliest.
Alone and Unafraid
As wargames have repeatedly noted, the US ability to consistently strike the mainland, particularly early in the conflict, will be limited and inconsistent, so we likely won’t be able to slow ASW operations from the air. Even if we could drop more ordnance on the mainland, ASW helicopters and aircraft runways likely wouldn’t be at the top of the targeting list. Moreover, local air cover for US submarines will likely be scarce. So US ability to intercept and/or deter PLA aircraft early in the conflict from conducting operations within a couple hundred miles of the Chinese shoreline will be incredibly unlikely. More or less, US submarines will be on their own for their survival the closer they get to the Taiwan Strait.
So, with US submarines forced to operate alone and unafraid around Taiwan, just how good are PLA sub hunters? Well, that’s a difficult question. As I said earlier, these sorts of operations are shrouded in more secrecy than most because of how pivotal they can be in shaping the battlefield. But what we know publicly suggests the PLA knows ASW is vital, that it is a deficiency, and that it is attempting to rapidly improve ASW lethality and readiness through new systems and training.
For reasons that go back to 1980s industrial policy, PLA aircraft largely underperform relative to their oceangoing counterparts. In simplest terms, the CCP correctly structured a shipbuilding industry that could compete with the rest of the world but they didn’t take the same direction with their aeronautical industry and it cost them. They’ve had to beg, borrow, and mostly steal US tech to try to catch up to our fixed wing and rotary aircraft. Even with those designs and large industrial base, the PLA still relies on a lot of shitty Russian aeronautical technology and parts. The Y-8 platform used for ASW and many other functions from electronic warfare to troop transport, is the workhorse of the PLAAF, but quite simply not on the same level as US ASW aircraft. In the last few years, the PLA has begun producing the KQ-200 to replace the older Y-8s as its main maritime patrol aircraft. This plane has a far better suite of electronics and sensors, and has been involved in more than half of all ADIZ incursions around Taiwan in the last few years. In summary, the KQ-200 looks to catch up to US ASW capabilities but it may take a few more years to reach parity in capability. Fortunately for the Chinese, they can produce far more of these to saturate the airspace than the US currently can in and around Taiwan. Once again, the Chinese are proving that quantity has a quality all its own. Still, Beijing is not putting all its eggs in the KQ-200 basket.
Spooky Action Underwater
There have been a number of articles in the last few years speculating on Chinese seabed-based sensors in the South and East China Seas, designed to illuminate and deny a submarine’s best defense: its stealth. If you can see and track a sub without fear of losing it or dedicating huge airborne resources to scouring the seas with sonar buoys, then you solve half the problem. Sonar buoys, the traditional air or sea-launched sensor that rides the waves and hunts for anything that shouldn’t be there, will undoubtedly be deployed in vast quantities by both sides as they set up roving traps for each others submarines. But what if China didn’t have to rely on temporary nets of sonar arrays, what if they could establish a permanent one that couldn’t be spoofed? Enter the legend of the quantum sensor.
I won’t get into the specifics of quantum mechanics here, but I’ll just say that in theory you could create a network of sensors based upon quantum principles that would not only detect any changes in that sensor picture, but would be impossible to spoof. In theory, that is a real thing that can happen. I know Chinese scientists have made some strides in this. But as I’ve written before, just because a technology exists in the lab doesn’t mean it’s ready for the field. I have no doubt the PLA is making every effort to create something akin to the old US SOSUS arrays in the North Atlantic to track hostile submarines, and it will be a real challenge for us, but I also don’t think they’re anywhere close to an all-seeing eye.
Between sensors and maritime patrols over such a small area, combined with improved PLA maps of the undersea world (sometimes stolen from us), they undoubtedly have a decent operating picture around Taiwan for sub hunting. But sensing is only part of the problem, can the PLA effectively use that information to hunt down and kill US submarines before they tear the invasion force to pieces?
The Real Unknown
Assessing weapons systems, particularly enemy systems, during peacetime can be incredibly difficult without published or otherwise acquired verified test data. As we’ve seen time and again in Ukraine, Russian systems underdelivered and ours were clearly undersold. Now, don’t mistake that comparison for me saying PLA systems are shit, you have to take each one as you find it and while each country has their struggling sectors, I would bet dollars to donuts that the PLA systems perform at a better rate than the Russians, and undoubtedly will give us a run for our money. All of this is to say, at least with public data, we know very little about this end of the killchain for PLA ASW. What we do know, is that the PLA once again emphasizes quantity in its missile stores and can undoubtedly produce a lot more munitions at a faster rate than we can. If the PLA can see our subs, and can sortie enough aircraft or ships in range, they can undoubtedly unload a world of hurt within the Taiwan Strait. If I’m commanding a Virginia-class sub, I’d prefer to place my bets on survival on disrupting PLA sensing than I am on whether or not their missiles can hit me once I’m tracked and targeted. This doesn’t even get into PLA development of unmanned underwater vessels (UUVs) that can augment sensing and targeting, although large-scale deployment of those systems for both the US and China are a few years out and their proper employment not yet clear.
So, if you’re a planner, staffer, or whomever reading this, and you want to know what you can do to keep our subs in the fight and the PLA blind under the waves, let me make a few suggestions.
-Don’t let the shiny distract you. Focus foremost on the here and now through the end of the decade. Quantum technology sounds scary but so do nanobots, both have an equally low likelihood of playing a serious role on the battlefield anytime soon. If you’re running ASW, it’s all about the sensor networks from buoys to seabed systems. If you’re running from ASW, it’s about decoys, spoofing, and choosing your shots. A target rich environment doesn’t necessarily mean a free-fire zone.
-Bump up those rookie numbers. It’s not just about building more submarines, although that is absolutely important. The shipbuilding industry needs a reliable plan and budget to work from. But, it’s also about ensuring our allies can add their subs to the fight from Day 1. The easiest way to level the numbers game with the PLA is to ensure Japan and Australia come to the fight on Day 1. AUKUS-backed nuclear subs are not a near-term solution, so their diesel subs will have to do. Given the limited range, we need to work out additional basing agreements or agreed upon AORs in order to maximize time on station and operational capability.
-Think outside the box. Frankly, the most effective way to improve US submarine survivability as PLA ASW capabilities improve is to limit the need for US submarines in and around the Taiwan Strait. In an ideal world, we have purchased and deployed enough seabed-based smart mines, armed or Kamikaze UUVs, and loitering munitions to strike the PLA invasion force *before* they hit the beaches. Buying and deploying these already developed or near-maturity systems are key to leveling the playing field and canceling out the ASW threat from the PLA mainland. Wars are won in the last 100 yards, not at a distance of 1000 miles. If you can’t find a way to get up close and make the enemy bleed while you live to fight another day, you can’t win. Running submarines as the chief hunter-killer in the Taiwan Strait is simply no longer the best option. While these cheaper systems hurt the invasion force in the Strait, our submarines are freed up to hunt down the PLA surface fleet. The sooner we sink that fleet and break the blockade, the sooner our fleet can arrive intact and well-armed to finish the job.
If you would like to read more about the future of US-China conflict, the invasion of Taiwan, and what the world looks like if Taiwan falls, check out my book, EX SUPRA. It just got nominated for a Prometheus Award for best science fiction novel! And if you have any suggestions for topics for future newsletters, please send them my way on Twitter @Iron_Man_Actual.
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