Artificial Islands Built on Continental Shelves as Future Risks in Spratly Islands Dispute

In today’s climate of uncertainty and shifting global power dynamics, a notable and ongoing dispute exists between several Southeast Asian nations and the People’s Republic of China over the Spratly Islands. This dispute encompasses various future risks, including vital shipping routes, overlapping territorial waters, competing claims to exclusive economic zones (EEZ), and territorial claims over islands and landmasses in the region. In addition, continental shelves play a central role in the disagreement, with states engaging in construction and expansion projects that further complicate the situation. Analysing these trends provides insight into potential future conflicts.

Before examining the situation further, it is important to clarify key terms. Artificial islands refer to man-made structures not formed naturally, often created by expanding small islets. Continental shelves are submerged extensions of continents, stretching from the coastline to a point called the shelf break. The Spratly Islands are an archipelago in the South China Sea, consisting of islands, islets, cays, and over 100 reefs. Historically, China has laid claim to many of these islands, arguing that their sailors and fishermen have long inhabited the region. China formalized this claim in 1947 with the Nine-Dash Line, asserting sovereignty over much of the South China Sea. However, over time, other countries such as the Malay Sultanate States, the Philippines, and Polynesian states also laid claim to and inhabited these islands, leading to the current, highly contentious dispute. Today, the situation is exacerbated by the presence of Chinese vessels in Vietnam’s waters and the resulting drive by various nations to build structures on artificial islands within their respective EEZs, posing significant security, economic, and environmental risks.

Several hypotheses have been put forward regarding the future of the dispute, with attention focused on possible research and development of oil rigs located beyond the limits of EEZs, as defined by the United Nations Convention on the Law of the Sea (UNCLOS). Additionally, undiscovered shipping routes and resources in Southeast Asian seas may further inflame tensions. China’s 1998 Exclusive Economic Zone and Continental Shelf Act granted rights to authorize drilling on the continental shelf, but it did not specify regulations regarding horizontal drilling. This could become an issue as new technological advances are developed. Although horizontal drilling remains expensive and challenging compared to vertical drilling, its future potential is of concern. For now, however, the strategic and security aspects of continental shelf development, particularly China’s military buildup around the Pearl River Mouth Basin, have drawn the most attention.

Recent developments have further escalated tensions, particularly with the joint sea and air patrols conducted by the Philippines in cooperation with the U.S. military. These patrols, which began near the northernmost islands of the Philippines close to Taiwan, have given the U.S. access to Philippine military bases strategically positioned near China. This military cooperation includes the deployment of navy vessels, combat aircraft, and reconnaissance planes. These measures have been driven by China’s expansive claims over the South China Sea, which extend far beyond its EEZ and overlap with those of neighbouring countries.

In addition to the Philippines, Vietnam has increased its activities in the region. Since 2021, Vietnam’s dredging and land reclamation in the Spratly Islands have significantly expanded the landmass, from 120 acres in 2012 to 750 acres in recent years. Speculation suggests that this expansion is intended for the construction of airstrips, although current efforts seem focused on enlarging the islands rather than building runways.

China, meanwhile, has been rapidly militarizing the region. In 2022, a U.S. admiral confirmed that China had fully militarized three islands in the South China Sea, equipping them with anti-ship and anti-aircraft missile systems, laser and jamming equipment, and fighter jets. Chinese-controlled reefs now host multi-story buildings, warehouses, hangars, seaports, runways, and radars. In addition to military infrastructure, China continues to expand its oil exploration efforts. In May 2023, China installed two new massive offshore oil rigs—Enping 20-4 and Haiji-2—in the South China Sea, with Enping 20-4 completed just days after installation. These offshore rigs are part of a broader oilfield development project that includes the Lufeng oil complex and others in the Pearl River Mouth Basin.

The Pearl River Mouth Basin, located to the east of Hainan Island in the northern South China Sea, is a crucial offshore oil-bearing region. This basin is vital to China’s energy independence and its long-term economic plans. To protect its interests in this area, China has taken steps to exert influence over nearby islands, particularly in the Spratly. Although China denies aggressive intentions, its military buildup and the strategic importance of the basin have raised alarm among Southeast Asian nations. This reflects China's embrace of offensive realism, which views control over key resources as essential to its economic dominance over the next five decades. The military presence around the Spratly is thus seen as necessary to protect valuable resources, particularly in the Pearl River Mouth Basin.

China's motivations may also be linked to its pursuit of critical minerals such as lithium and cobalt, which are essential for battery production and the development of electric vehicles. As a leader in advocating for Sustainable Development Goals (SDGs), particularly in clean energy, China has channelled significant resources into expanding its dominance in this sector. In December 2022, China unveiled its first oceanographic drilling ship, designed to extract minerals from depths of 10,000 meters. This ship, launched by the China State Shipbuilding Corporation, represents a significant step in China’s efforts to tap into new mineral resources in the South China Sea. In the future, continued research and technological development may enable China to discover new deposits in the Spratly Islands, intensifying territorial disputes. The extraction of these minerals, however, poses not only security and economic risks but also significant environmental concerns, as deep-sea mining and battery production generate substantial pollution.

In conclusion, the dispute over the Spratly Islands remains a complex and ongoing issue, with China’s expansive Nine-Dash Line claim at the centre of tensions. China views the South China Sea as a critical economic zone, essential to its energy independence and future economic growth. Its investments in oil exploration and development, particularly with the potential for horizontal drilling, raise concerns about the environmental impact on the region's seabed. Military buildups by China, the Philippines, and Vietnam further exacerbate tensions, with all parties constructing infrastructure and fixtures on their claimed artificial islands. China’s strategic interests in the Pearl River Mouth Basin underline its need to secure the region for economic and security reasons. As these disputes intensify, international bodies like the Asia Maritime Transparency Initiative may need to address the growing security threats posed by the territorial conflict. The dispute has significant implications for regional security, economic cooperation, and environmental sustainability in Southeast Asia.