China’s military aims to target U.S. undersea sensor network analysis
A professor at the U.S. Naval Academy stated that Chinese experts believe “the U.S. underwater surveillance system has many vulnerabilities.” In April 2019, a Chinese Navy submarine participated in a naval parade near Qingdao in Shandong Province.
Submarines are a crucial component of the Chinese Navy’s strategy. Chinese experts warn that the U.S. underwater sensors pose a significant threat to these submarines.
As a result, some officers of the People’s Liberation Army Navy advocate for systematically destroying the U.S. underwater sensor network during wartime. This includes using various countermeasures, from underwater drones to China’s vast commercial fishing fleet, to destroy, disrupt, or deceive underwater microphones.
Ryan Martinson, a professor at the China Maritime Studies Institute of the U.S. Naval War College, wrote in an article for the International Maritime Security Center that Chinese experts believe, “the U.S. underwater surveillance system has many vulnerabilities, and the scale of the Western Pacific battlefield exacerbates these vulnerabilities. If enough nodes degrade in performance, the entire system could lose functionality.”
Ironically, the views of the U.S. and China regarding the balance of underwater power seem to be completely opposite. The U.S. and its Pacific allies are concerned about China’s growing submarine fleet. The Pentagon predicts that China’s submarine fleet will reach 65 vessels this year and 80 by 2035. China currently has the capability to deploy six ballistic missile submarines and six attack submarines, in addition to a large number of conventional submarines equipped with anti-ship missiles, including 21 advanced Yuan-class diesel-electric submarines.
On the Chinese side, there are concerns that the U.S.’s intensive anti-submarine warfare (ASW) operations have made Chinese submarines overly vulnerable.
“The Chinese Navy is investing in submarines because it recognizes the tremendous potential deterrent and operational value of submarines,” Martinson wrote. “However, this value depends on the submarines’ ability to remain undetected underwater. Yet, according to Chinese military experts, this fundamental requirement cannot be guaranteed—indeed, it is far from it.”
Martinson analyzed an article published by three Chinese Navy officers in the internal military journal Military Digest in November 2023.
Martinson noted, “This allows the authors to candidly share their expertise, a candor that is rarely (if ever) found in the PLA’s public materials.”
The article in Military Digest expresses concerns that Chinese submarines are outmatched by what the authors describe as an “integrated three-dimensional surveillance system.” This includes warships, submarines, aircraft, satellites, underwater drones, underwater microphones of the Integrated Undersea Surveillance System (IUSS), and surface vessels equipped with Surveillance Towed Array Sensor System (SURTASS).
The U.S. believes that China has an underwater fleet, while China believes that the U.S. is attempting to achieve “unilateral transparency” underwater. From China’s perspective, the “dragnet” of anti-submarine warfare is so extensive that it uses survey vessels to map the seabed topography and water conditions for optimal submarine detection and employs ocean surveillance vessels to capture the acoustic signatures of submarines.
During the Cold War, the U.S. and its allies established several chokepoints—such as the Greenland-Iceland-United Kingdom (GIUK) gap—that Soviet submarines needed to pass through to navigate the heavy encirclement of anti-submarine vessels, aircraft, and seabed sensors to reach the North Atlantic. Today, some Chinese experts believe that the U.S. can prevent its submarines from “entering vital maritime routes, threatening their ‘navigational safety’ during training and operational areas,” Martinson wrote. Beijing is particularly concerned about the safety of its six nuclear ballistic missile submarines.
The article in Military Art states, “The likelihood of Chinese submarines being detected when leaving port is extremely high.” “The chances of Chinese submarines being detected and intercepted while operating in nearshore waters are quite high.”
Martinson points out that, conversely, this acknowledgment is a devastating indictment of “the operational effectiveness of the Chinese submarine force.”
One question is whether these Chinese officers are exaggerating the power of U.S. anti-submarine warfare, perhaps to secure more resources or to lobby for a more aggressive U.S. maritime policy. However, Brian Clark, a researcher at the Hudson Institute and a former U.S. Navy submarine officer, believes that “their overall assessment is realistic.”
Clark told Defense News, “For decades, the IUSS network, composed of fixed arrays and SURTASS, has been able to effectively track submarines in critical areas.”
In September 2022, the U.S. Navy, Japan Maritime Self-Defense Force, and South Korean Navy held trilateral anti-submarine warfare exercises east of the Korean Peninsula.
Regardless, some response from China to the U.S.’s large-scale anti-submarine plans is inevitable. In recent years, China has placed great emphasis on disrupting the nervous system of the U.S. military: a complex and expensive network of integrated communications, sensors, weapons, and command and control systems. Unsurprisingly, Chinese authors advocate using similar methods to exploit multiple vulnerabilities in the U.S. anti-submarine warfare system.
First, according to the article in Military Art, China’s own conventional military capabilities have improved to such an extent that U.S. anti-submarine warfare platforms (such as aircraft and ships) can no longer operate near Chinese territory. Moreover, as some in the Trump administration agreed, the U.S. military is already overstretched.
More directly, the Chinese military can destroy various nodes within the U.S. anti-submarine warfare system.
“Undersea cables and arrays are ‘quite vulnerable and easily cut,'” while command and control systems—what Chinese officers refer to as the “fatal weakness” of the U.S. underwater sensor network—could be destroyed or disrupted by kinetic attacks or cyber warfare.
To defeat U.S. anti-submarine warfare in the Pacific region, Chinese experts urge for an intensive offensive that requires long-term planning and resource investment.
“At the national strategic level, China needs to combine defensive measures with countermeasures, but must place greater emphasis on countermeasures,” Martinson explains. “This means prioritizing the development of capabilities that can ‘attack and destroy’ the U.S. underwater surveillance system.”
These new capabilities will include utilizing acoustic, magnetic, optical, and electronic detection as well as artificial intelligence technologies to locate hidden underwater sensors and drones. The authors also call for the development of unmanned underwater vehicles to destroy U.S. sensor arrays.
Clark questions how easily China can disrupt the U.S. anti-submarine warfare network.
“The PLA could easily attack deployed submarines when conflict breaks out, and may even attack small vessels or fixed arrays supporting the IUSS,” he said. “However, such actions would divert forces from other missions and could take considerable time.”
“Searching for small objects in the water or near the seabed is difficult,” Clark added. “Such actions would also limit the PLA’s underwater forces to within the First Island Chain, where these forces are best deployed outside the First Island Chain during conflict.”
Nevertheless, there are indeed some weaknesses in U.S. anti-submarine warfare that China can exploit.
“The PLA may be able to suppress the IUSS by deploying large submarines before conflict, achieving better results,” Clark said. “The U.S. military would be unable to attack PLA submarines, and the number of U.S. submarines and destroyers is insufficient to track all deployed PLA submarines.”
Ultimately, it remains to be seen whether China’s civilian and military leadership will adopt the Navy’s recommendations.
“Nevertheless, these recommendations are being discussed by serious experts, which means the PLA Navy may be considering them,” Martinson warns. “Therefore, U.S. Navy leaders must take them seriously as well.”
Translated from Military Research Institute, Defense News/ Asia Pacific/ Aug 14, 2025.