The U.S. Navy Submarine Force Could Sink The Chinese Fleet And Save Taiwan, But At The Cost Of A Quarter Of Its Boats (2024)

If and when China attacks Taiwan, the U.S. Navy’s submarines could be the first defenders to take shots at the Chinese invasion fleet.

How many Chinese ships the American attack boats can sink, and how quickly, could make all the difference in the apocalyptic “ultra-mega” war, to borrow a phrase from Ian Easton, an analyst with the Virginia-based Project 2049 Institute.

A successful U.S. submarine campaign could help bring the war to a swift end, preserving Taiwan’s independence and blunting China’s global ambitions. A failed undersea campaign, by contrast, could invite Chinese dominion over Taiwan and the whole Western Pacific region.

Win or lose, the U.S. Navy should brace for heavy losses. Even a victorious USN sub fleet could suffer staggering losses in battle with the Chinese navy around Taiwan.

That’s one sobering result of a series of war games organized by the Center for Strategic and International Studies in Washington, D.C. In most of the 24 iterations of the game, “submarines were able to enter the Chinese defensive zone and wreak havoc with the Chinese fleet,” analysts Mark Cancian, Matthew Cancian and Eric Heginbotham concluded.

But even in the scenarios that were optimistic for Taiwanese and allied victory, the U.S. undersea force, which today numbers 53 nuclear-powered attack and cruise-missile submarines, lost up to a quarter of its boats and thousands of sailors.

The losses are indicative of the intensity of the submarine campaign that CSIS projected. The think-tank assumed the U.S. would commit all or most of its undersea fleet to a war with China, perhaps setting aside just a few boats to continue shadowing Russian ballistic-missile subs.

The 40 or 50 submarines would organize in squadrons of four boats apiece and deploy to U.S. bases in Guam, at Wake Island and in Yokosuka, Japan. One squadron should be on station in the narrow Taiwan Strait when the first Chinese rockets fall and the invasion fleet sets sail.

In CSIS’s war games, those four boats sank Chinese ship after Chinese ship until their torpedoes and missiles ran out or Chinese forces hunted them down. The other nine or ten USN sub-squadrons meanwhile synchronized into what the Cancians and Heginbotham described as an undersea “conveyor belt.” “They hunted, moved back to port, reloaded, then moved forward again and hunted,” the analysts explained.

“Each submarine would sink two large amphibious vessels (and an equal number of decoys and escorts) over the course of a 3.5-day turn,” the Cancians and Heginbotham wrote. In two weeks of intensive fighting, the submarines sank as many as 64 Chinese ships, including many of the PLA Navy’s biggest amphibious ships and surface combatants—and potentially some of the PLAN’s aircraft carriers, as well.

The Chinese ships that succeeded in avoiding American submarines weren’t safe, of course. The same CSIS war games found that U.S. Air Force bombers firing stealthy cruise missiles posed an even greater danger to Chinese ships than did U.S. Navy subs.

In the scenario where the Taiwanese and their allies won most decisively, the Chinese amphibious and transport fleet lost 90% of its ships—and was unable to supply the few Chinese battalions the fleet had managed to land on Taiwan. With no sea lines of communication, Chinese troops on the island quickly ran out of fuel and ammunition.

But even that decisive victory came at a high cost for the Americans. Chinese escorts, aircraft and submarines sank a fifth of the deployed American subs every three or four days throughout the two-week war. In the end, perhaps a dozen or more American submarines lay wrecked at the bottom of the Pacific Ocean, radioactive tombs for as many as 2,000 submariners.

In light of their disproportionate contribution to the Taiwan campaign, submarines absolutely should be a top priority in U.S. defense planning, the Cancians and Heginbotham wrote. “Given the value of submarines, acquiring more is an obvious recommendation.”

That’s easier said than done when a single nuclear attack boat costs around $3 billion and just a handful of American shipyards can build their components. The Pentagon plans to acquire two attack boats a year for the foreseeable future in order to maintain, and eventually grow, the overall undersea force.

“The U.S. Navy should commit to funding those two per year even if shipbuilding funds get tight,” the CSIS analysts recommended. The Navy also could speed up the sub fleet’s expansion by keeping older boats in service longer.

If the think-tank’s war games are predictive, the U.S. fleet will need every submarine it can muster in order to defeat a Chinese invasion of Taiwan.

This story has been updated to correct some of the submarine-attrition calculations.