China has bolstered its listening post capacity in Cuba. Image: Twitter Screengrab

China has recently upgraded its spy facility in Cuba, adding more listening power to a global network that increasingly threatens to alter the undersea nuclear balance of power and potentially spark new rounds of nuclear proliferation. 

This month, the Wall Street Journal reported that China and Cuba have together built a new intelligence-gathering training facility in Cuba, from where the two communist allies could potentially and will likely seek to intercept US military communications, tech industry secrets and maritime transmissions.

The Wall Street Journal report notes that China is trying to replicate US global surveillance capabilities and that Cuba could play a crucial role in the scheme. Both China and the US already operate listening posts around the world as part of their signals intelligence (SIGINT) programs, which are known to eavesdrop on voice conversations, text messages, emails, location, signals and data transmissions.

The Wall Street Journal notes that US officials announced in June that China had struck an agreement worth several billion dollars with Cuba to build a new military facility capable of electronic eavesdropping just a hundred miles from the southern US state of Florida.

The report also mentions that US officials say China and Cuba already jointly run four eavesdropping stations on the island, with experts noting this is just the latest chapter in a long history of Cuba’s involvement in helping US near-peer adversaries’ eavesdropping.

The Wall Street Journal says a Chinese listening post would have a clear mission: to eavesdrop on satellites, which convey much of the world’s and US’ military, diplomatic and commercial information.

The report says that satellite dishes on purported SIGINT facilities such as those run by China in Cuba can range from a single dish to over a dozen, allowing the station to target multiple satellites simultaneously.

The report points out that China primarily focuses on commercial eavesdropping, with enormous amounts of technological communication going back and forth between Silicon Valley and other areas.

It also says that China’s Cuba SIGINT facilities could have a direction-finding apparatus known as an “elephant cage” or “wullenweber,” which are giant antennas with 360 elements in a circle.

It notes that such a device can track maritime activity, with Cuba strategically located to pick up signals along the US East Coast and triangulate the location of US nuclear submarines in conjunction with China’s similar facilities worldwide.

The initial US response to reports of the new Chinese facility has been a mixture of contradiction and denial. In a June 2023 Politico article, Alexander Ward points out that the White House and Pentagon initially called the reports “inaccurate”, but later clarified that the Chinese base in Cuba had already been established. Ward also mentioned that the Chinese spying effort is an ongoing concern and that the US has taken steps to deal with it.

He mentions that China upgraded its intelligence collection facilities in Cuba in 2019, which is well-documented in the intelligence record. Ward also said that US President Joe Biden directed his administration to address the issue within months, noting that the thrust of the engagement with Beijing over the spy post has been through diplomacy.

However, Ward mentions that Representative Mike Turner, chair of the House Intelligence Committee, criticized the Biden administration for contradicting themselves multiple times about whether or not the Chinese Communist Party (CCP) is spying on the US from Cuba.

He also stated that Representative Mike Gallagher, chair of the House China Committee, slammed the Biden administration’s response to the initial reports. Moreover, he says Representative Ritchie Torres, a member of the same panel, said the news of the base is “sufficiently plausible to merit congressional oversight.”

The two leaders of the Senate Intelligence Committee released a joint statement in response to the news, stating that it would be unacceptable for China to establish an intelligence facility within 100 miles of Florida.

Aside from its purported spy base in Cuba, China may operate similar facilities in the Indian Ocean and adjacent to the South China Sea. In April 2023, Asia Times reported on China’s possible spy facilities on Myanmar’s Great Coco Island and at Cambodia’s Ream Naval Base.

Satellite imagery from US-based Maxar Technologies has revealed that construction work has resumed on Myanmar’s Great Coco Island. The images show that a 2,300-meter runway has been extended, leading to suspicions that China may be responsible for the development.

It is believed that China is aiming to use Coco Island as a listening post in the Indian Ocean, giving it a strategic advantage over the Indian Navy in information gathering and positioning.

Reports indicate Coco Island could also serve as a possible forward defensive position for the Beijing-financed Kyaukpyu Port, the maritime terminus of the China-Myanmar Economic Corridor (CMEC) which reaches from China’s southern Yunnan province to the Indian Ocean.

Around the same time, the Cambodian government announced China-funded plans to build an air defense center and expand a radar system near the Ream Naval Base.

The Cambodian government has denied persistent allegations and reports suggest that the base is being upgraded into a Chinese spy hub for the South China Sea. If so, it would be its first overseas base in the Indo-Pacific region.

China’s SIGINT facilities in Cuba and possibly Myanmar and Cambodia may add to its growing array of submarine detection technologies, significantly improving its strategic deterrence vis-à-vis the US.

Asia Times has previously reported on China’s use of terahertz technology and extremely low frequency (ELF) signal detection to track US nuclear submarines. Advances in sensor resolution, processing power and machine autonomy have expanded the range of detectable signals, enabling the distinction of previously indistinguishable signals.

Commercial and open-source technologies like satellite imagery, synthetic aperture radar (SAR) and social media tracking enhance the ability to identify submarine fleets, track submarine developments and discern patrol patterns.

Such technologies add to the growing transparency of the world’s oceans, which can reveal US covert operations to shadow China and Russia’s nuclear ballistic missile submarines (SSBNs) using inuclear attack submarines, which can lead to nuclear retaliation from the latter if their underwater nuclear deterrents are perceived to be under threat.

Such developments can also threaten US extended deterrence guarantees to crucial allies such as South Korea and Japan, as near-peer submarine detection capabilities can undermine the security of US SSBNs.

That can potentially erode confidence in America’s second-strike nuclear capabilities, making it reluctant to assist its allies without the safety of its nuclear umbrella and adding incentive for the latter to develop nuclear arsenals of their own.