Deep Sea, Deeper Debt: How China Is Weaponising The Ocean Floor And Economic Fragility – Analysis
In a secluded shipyard along China’s eastern seaboard, a recently unveiled vessel carrying capabilities once confined to spy thrillers. Developed by the China Ship Scientific Research Centre, this vessel deploys a diamond-coated grinding wheel capable of severing armoured subsea cables at depths of up to 4,000 meters—double the operating depth of most existing infrastructure. The implications are profound.
Ninety-five percent of the world’s digital communication—including financial transactions and military command signals—runs through these delicate undersea cables. Now, China has the explicit capability to disrupt this global lifeline.
This is no hypothetical scenario. In February 2025, Taiwanese authorities detained a Chinese-crewed vessel suspected of deliberately cutting undersea cables connecting Taiwan to its outlying Penghu Islands. Earlier incidents in the Baltic Sea in 2023 and near Taiwan’s Matsu Island in 2024—where Chinese ships were implicated in suspicious cable damage attributed to “anchor dragging”—highlight a troubling pattern. Previously shrouded in plausible deniability, these isolated acts now appear to represent early tests of Beijing’s new maritime sabotage capabilities.
Experts express growing alarm at this development. A recent CSIS analysis starkly noted, “The tool’s 4,000-meter capability marks a paradigm shift in undersea warfare.” Analysts fear that this strategic tool, integrated into deep-sea submersibles like China’s sophisticated Fendouzhe, could cripple entire nations economically and militarily, virtually overnight, without firing a single conventional weapon.
Ports of Call, Debt of Control
China’s strategic ambitions beneath the waves complement its longstanding practice of “debt-trap diplomacy,” a calculated financial leverage strategy deployed across Africa, South Asia, and beyond. In the Indian Ocean alone, Beijing currently controls or finances over 21 strategic ports. The now-infamous case of Sri Lanka’s Hambantota Port—leased to China for 99 years after Sri Lanka defaulted on loans amounting to $1.5 billion—illustrates the predatory model that has left governments wary of Chinese investment.
Yet, despite this cautionary tale, many countries remain trapped in spiralling debt obligations. Zambia, for instance, owes Chinese creditors an estimated $6.6 billion, double the figure initially disclosed. Approximately half of Kenya’s national revenue is diverted toward servicing Chinese debt. According to the Associated Press, 12 additional nations are teetering dangerously close to economic collapse under unsustainable Chinese loans, and their strategic assets—including ports, mineral resources, and infrastructure—are at risk of seizure.
Gwadar Port in Pakistan stands as a particularly worrying example. The port’s planned expansion reportedly includes accommodation for half a million Chinese nationals and infrastructure suitable for PLA naval use. These opaque contracts serve dual purposes, enhancing commercial access while quietly enabling military projection.
Environmental Devastation and Human Rights Abuses
Behind these financial schemes lies another grim legacy: severe ecological harm and human rights abuses. In March 2025, a tailings dam collapse at the Sino-Metals Leach mine in Zambia discharged 50 million litres of toxic acidic waste into the Mwambashi River, directly affecting over 700,000 residents. Crops were devastated, and water supplies poisoned. Local communities watched helplessly as decades of environmental safeguards were discarded under the weight of Zambia’s financial dependence on Chinese creditors.
Further offshore, China’s rush into deep-sea mining—accelerating in recent years with polymetallic nodule extraction trials—is proceeding without adequate environmental oversight. Ecologists have warned of irreversible biodiversity loss, yet these warnings have largely gone unheeded as economic dependencies silence host nations’ objections.
Fishing Fleets or Maritime Militias?
China’s vast distant-water fishing fleet is equally concerning, numbering more than 2,500 vessels operating across the Indian Ocean region. A comprehensive 2024 investigation by the Environmental Justice Foundation documented rampant illegal fishing, widespread shark finning, dolphin killings, and abusive labour practices onboard these Chinese-operated vessels.
Even more troubling, satellite analysis indicates these civilian vessels frequently operate in coordinated patterns near contested reefs and sensitive military installations, performing dual roles as reconnaissance and surveillance platforms for the People’s Liberation Army.
India’s Navy Chief, Admiral Dinesh Tripathi, highlighted the severity of the threat, stating publicly that many Chinese vessels in the Indian Ocean “are not doing what they claim to be doing,” reinforcing the reality that the boundary between civilian and military activity in Chinese maritime policy has blurred beyond recognition.
India’s Alternative Vision: Partnership over Predation
In response to these growing threats, India is positioning itself as a credible and responsible counterweight, emphasising transparency and cooperative regional security. Unlike Beijing’s predatory infrastructure deals, India’s maritime initiatives, such as the recent Africa-India Key Maritime Engagement (AIKEYME) exercises involving ten African nations, underscore collaborative security and mutual respect for sovereignty.
India’s ambitious Deep Ocean Mission, featuring the recently tested submersible Matsya-6000—which aims for operational depths up to 6,000 meters by 2026—starkly contrasts China’s militarised deep-sea ambitions. India’s programme prioritises scientific research, sustainable resource use, and environmental preservation while openly sharing data and engaging in international dialogue.
Strategically located initiatives like the Chabahar Port in Iran provide regional partners viable alternatives to China’s coercive models, aligning with India’s Security and Growth for All in the Region (SAGAR) and doctrine advocating for mutually beneficial regional development.
A Crossroads Beneath the Waves
Today, the ocean depths represent a troubling new frontier of geopolitical rivalry, layered intricately with technology, finance, and statecraft. China’s emerging capability to sever undersea cables marks a disturbing escalation in grey-zone tactics, complementing and amplifying the vulnerabilities created through years of debt entanglement and strategic coercion.
Yet, the international community is not powerless. Awareness and vigilance have increased significantly, with nations actively seeking alternatives to China’s opaque partnerships. As the seabed rapidly transforms into the latest contested battleground, the imperative grows for countries across Africa, Asia, and beyond to choose collaborative resilience over predatory dependence and multilateral transparency over unilateral exploitation.
The message for governments weighing short-term financial incentives against long-term sovereignty and security is increasingly clear: debt taken lightly today may become shackles of strategic subjugation tomorrow. As China’s deep-sea ambitions surface, nations worldwide must urgently decide whether the future of the ocean floor belongs to collaboration and transparency—or coercion and strategic weaponisation.
