China’s recent announcements of new submarine-hunting technologies are probably more hype than hardware, but they highlight Beijing’s goal of countering the threat posed by U.S. attack boats, which remain essential to U.S. war plans. The U.S. submarine force will not be able to rest on its laurels as the world’s finest for much longer. Soon it will need new approaches and capabilities to operate and potentially fight in the bastions that China and Russia consider their home waters.
China has been trying to up its anti-submarine warfare game for more than a decade. Today, sonar arrays like the United States’ Cold War-ear Sound Surveillance System network listen in the East and South China seas as well as the waters U.S. submarines would need to transit from Guam or Hawaii. They are complemented by capable low-frequency active sonars on Type 056 Jingdao-class corvette that would obviate the superior sound silencing of U.S. submarines. Around the most protected areas, like the Taiwan Strait, Chinese forces are likely to deploy mines as well.
Since the Cold War, the U.S. submarine force has relied on its stealth to surveil opponents and threaten denial or retaliation. When the primary targets of U.S. submarines were Soviet submarines in the far north or Soviet fleets in the open ocean, stealth was sufficient. After U.S. submarines launched attacks and could be detected, their targets were likely consumed with defense more than anti-submarine warfare.
Against China, and perhaps Russia, this dynamic no longer holds. U.S. submarines will likely need to launch missiles or torpedoes close to enemy coasts. While their targets may be tied up with defense, the rest of the enemy’s forces at sea and ashore can devote themselves to counterattacks. U.S. submarines could find themselves on the run after their initial salvos and unable to further contribute to the fight.
To avoid being marginalized like hundreds of German U-boats late in World War II, U.S. submarines will need to suppress or confuse the sensors China or Russia will depend on for undersea detection and targeting. In many ways, they face the same challenge as aviators conducting strikes in the face of modern air defenses. And like their aerial counterparts, U.S. submarine forces will need to employ jamming, decoys, deception and destruction to break into contested areas undersea.
Another challenge submariners will share with aviators is how to suppress or defeat enemy defenses without giving up strike capacity in the process. U.S. air forces in Vietnam, facing the first generation of Soviet surface-to-air missiles, had to divert about a third of their strike packages to countering North Vietnamese defenses even though the new SA-2 was only effective about 2% of the time.
Uncrewed vehicles would be the best choice for deploying the acoustic jammers, radar and sonar decoys, and explosive warheads that will suppress or defeat Chinese or Russian undersea sensors or mines. But to preserve the submarine’s weapons capacity and reduce its likelihood of detection, most of these vehicles should be launched by someone else.
Confusing or attacking enemy sensors depends on accurate targeting, which the challenges of undersea sensing and communication will make nearly impossible in real time. Instead, U.S. undersea forces will need to survey adversary sensors and networks in advance. Large uncrewed undersea vehicles, like the Navy’s now-canceled Snakehead or the commercially available Remus 6000, could gather this intelligence, which may be impractical with smaller UUVs that may lack the necessary endurance or depth.
However, medium and small UUVs launched from shore, aircraft or unmarked ships would be well-suited to jamming and deception missions. Vehicles such as the in-development medium UUV or Lionfish small UUV could carry decoy systems like those on the Navy’s Expendable Mobile Anti-Submarine Warfare Training Target that emulates submarine tones to draw attention away from U.S. undersea operations. And to obscure both real and simulated submarine undersea activity, small or medium UUVs could carry noisemakers like those on existing active torpedo countermeasures.
The confusion created in the enemy’s underwater picture by decoys, jamming and actual U.S. submarine operations would likely overwhelm the still relatively small anti-submarine warfare response capacity of Russia or China. However, U.S. submarines will need the ability to stand and fight when attacks come, rather than evade and regain their stealth. This will demand improved combat systems that can predict the effectiveness of an enemy attack and can guide new counter-torpedo weapons, much like the Aegis system and surface-to-air missiles do for surface combatants.
Once U.S. submarines reach the most contested areas where they are needed to launch missile attacks deep into enemy territory or stop ships invading an ally, they will still likely face the threat of undersea mines. This mission is where sub-launched and -recovered medium UUVs will be essential for finding a path around mines or — if necessary — destroying them.
The changes these operational concepts imply will be substantial. Instead of being the silent service, the U.S. undersea force will need to generate noise and hide in the resulting chaos. And rather than being alone and unafraid, U.S. submariners will need to rely on a team of crewed and uncrewed platforms on, above and below the water to reach their targets. Otherwise, America’s world-leading submarine force could find itself viewing the action from the sideline.
Bryan Clark is a senior fellow and the director of the Center for Defense Concepts and Technology at the Hudson Institute think tank.
