China ready for undersea cable attacks, congressional report warns

NEWS AND ANALYSIS:

The Chinese government is developing capabilities for cutting undersea communications cables as part of its large-scale military buildup and preparation for war, according to a congressional report.

The report by the U.S.-China Economic and Security Review Commission reveals that as part of China’s plans for “gray zone” warfare — activities below the level of kinetic conflict — new cable-cutting technologies are being deployed.

“China has increasingly engaged in undersea cable-cutting activities as a gray zone pressure tactic, and there is mounting evidence that Beijing is developing new cable-cutting technologies for potential wartime use,” the report said.

Chinese researchers at institutions linked to the People’s Liberation Army are actively researching strategies for severing undersea cables, the report said. Numerous Chinese patents were filed for technologies designed to cut deep-sea cables cheaply and efficiently.

Undersea cables are the backbone of modern global communications infrastructure and transmit an estimated 95% of all global internet traffic. The links are used for financial transactions, government services, commercial activities and military communications.

The report reveals that in February, Chinese scientists at the China Ship Scientific Research Center, which was sanctioned for acquiring U.S. goods for the PLA, made public a new design for an “electric cutting device for deep-sea cables.” The device is said to be capable of severing armored cables at depths of more than 13,000 feet.

According to the report, the Chinese military is expected to sever undersea cables around Taiwan to crush the island’s communications during an invasion.

Researchers obtained a Chinese database showing “strategic points of interest” in Taiwan that included numerous undersea cable landing stations.

“Chinese vessels have sabotaged critical undersea cables near Taiwan and in the Baltic Sea,” the report said.

“Since the beginning of 2025, there have already been two incidents in which Chinese-owned ‘shadow fleet’ vessels cut cables near Taiwan while engaging in highly irregular movement patterns and disguising their identities and locations,” it said.

A Chinese vessel also cut two undersea cables in the Baltic Sea in November 2024. One connected Sweden and Lithuania and a second cable linked Germany and Finland.

The ship cut the cables by dragging its anchor for over 100 miles. The report said a Russian sailor was part of the Chinese ship’s crew and European investigators concluded that the captain had been instructed by Russian intelligence agencies to sever the cables, the report said.

That attack was similar to a Chinese vessel carrying Russian sailors in October 2023 that dragged its anchor and severed a Baltic Sea connector gas pipeline and an undersea cable linking Finland and Estonia.

“China has also interfered with the process of repairing undersea cables in the South China Sea, and U.S. officials have warned that China could use its cable repair ships to engage in espionage targeting the United States and its allies and partners,” the report said.

China, in another case, blocked Vietnam from repairing damaged undersea cables in the South China Sea, where both nations are locked in a dispute over control of the Paracel Islands.

China has asserted that the incidents were the result of accidents.

“U.S. officials have also expressed concern that Chinese cable repair ships could compromise the security of U.S. cables in the Pacific by placing taps on undersea cables and conducting reconnaissance on U.S. military communication links under the pretext of conducting repairs,” the report said.

“Taken together, these activities illustrate that China is developing both the tools and the operational experience to target global communications infrastructure in a future conflict — posing a direct threat to U.S., allied, and partner connectivity in a crisis,” the report said.

In March, Chinese engineers at the ship research center unveiled a compact, deep-sea cable-cutting device that can cut through the most fortified underwater communications or power lines, the Hong Kong-based South China Morning Post reported.

The new tool can cut cables as deep as 13,123 feet and is deployed on advanced manned and drone submersibles.

The newspaper reported that cutting cables near strategic choke-points such as Guam, a strategic U.S. military hub in the Pacific, “could essentially destabilize global communications during a geopolitical crisis.”

The House Homeland subcommittee on transportation and maritime security is set to hold a hearing on foreign adversary threats to undersea cables on Thursday.

Space Force faulted for failing to build weapons

China’s military has deployed multiple space warfare systems capable of destroying and disrupting U.S. satellites vital for military operations, while the U.S. Space Force so far remains constrained from developing its own space weapons in response, according to a congressional report made public Tuesday.

The latest annual report of the U.S.-China Economic and Security Review Commission warns that China is eclipsing the U.S. as the world’s leading space power — and threatening U.S. military and civilian space systems.

The report said China’s rapid expansion of space power “should concern all Americans.”

The threat is not limited to the military sector but includes Chinese space capabilities that can threaten vital satellite services affecting the health and welfare of all Americans, the report said, noting that satellites remain vulnerable to attack.

“Although the U.S. Space Force was established at the end of 2019 with the mission of ensuring continued U.S. space superiority, longstanding policy constraints have placed effective limits on its ability to achieve its critical mission,” the report said.

“These constraints include limits on developing and using offensive counterspace capabilities like ASAT weapons, electronic jamming, and cyber operations as well as limited resources to update legacy systems or build new capabilities.”

The constraints are in sharp contrast to China’s space arsenal. China invested heavily in building space weapons that can destroy or disrupt satellites that would “incapacitate” U.S. communications, intelligence, missile warning and undermine the military’s ability to conduct joint operations and project power, the report said.

The weapons include three types of ground-based anti-satellite missiles, robot satellites that can grab and destroy satellites without causing debris, and electronic and directed energy anti-satellite weapons.

“While China has continued to actively pursue both offensive and defensive counterspace capabilities, the United States has refrained from developing an offensive space program and has dutifully sought to avoid actions that could be seen as ‘weaponizing space,” the report said.

“Losing U.S. leadership in space would amount to relinquishing the advantage first secured during the original space race — when space became essential to military superiority, global prestige, and geopolitical influence,” it said.

Space Force Chief of Operations Gen. Chance Saltzman told the commission that Chinese space weapons pose a significant threat.

“Taken as a whole, China’s potent and expanding arsenal of space-based capabilities multiplies its combat potential many times over … China can hold U.S. and allied forces at risk with long-range precision weapons, preventing our forces from taking meaningful action before they even reach theater. The consequence of failing to mitigate this threat means military objectives will be tough to meet without unacceptable loss of American lives,” the general was quoted in the report as saying.

The commission did not directly recommend that the Space Force build counterspace weapons but called for boosting spending for the Space Force to “achieve space control and establish space superiority against China’s rapidly expanding space and counterspace capabilities.”

Report: PLA purges sought greater military loyalty

Recent large-scale purges of top military leaders in the People’s Liberation Army are part of a campaign by Chinese President Xi Jinping to ensure greater loyalty, according to the annual U.S.-China Economic and Security Review Commission report.

Mr. Xi has set two goals for the PLA — rooting out corruption and deploying advanced military technology with the ultimate goal of producing a military capable of conducting a successful invasion of Taiwan, the report said.

Experts queried by the commission were divided on the impact of more than a dozen high-ranking PLA officers being ousted over the past several years.

Purges and corruption investigations of senior PLA leaders will likely hinder weapons modernization, create instability among commanders, and erode troop morale, the report said, noting that the impact could undermine PLA combat effectiveness in the short term.

Other analysts told the commission that Mr. Xi views the short-term instability caused by advancing more politically reliable commanders as necessary for ensuring compliance with his political agenda, setting examples for other commanders, and making sure the PLA abides by his directions, the report said.

The purges expanded in the last year to reach new branches of the PLA with “deepening intensity,” the report said.

The firing of officers from the PLA’s Political Work Department, in charge of ideological discipline, is a sign that the purges are not limited to financial misconduct.

From July to December 2023, at least 15 senior PLA officers and defense industry leaders were fired, many linked to the PLA’s Rocket Force and the Equipment Development Department.

Key firings this year included Central Military Commission Vice Chairman Gen. He Weidong; CMC Political Work Department Adm. Miao Hua, and Lt. Gen. Tang Yong, deputy secretary of the Military Discipline Commission, in charge of anticorruption.

“The breadth of these investigations underscores Xi’s determination to enforce political loyalty at every level of the military hierarchy — an effort that, while disruptive in the short term, strengthens the CCP’s control over the armed forces given increased risks of potential external conflict,” the report said.

• Contact Bill Gertz on X @BillGertz.