History and Sovereignty of South China Sea (SCS)

12 February 2025

SCS 9-dash line and UNCLOS The terms “nine-dash line” and “twelve-dash line” refer to demarcation lines used by China to indicate its claims in the South China Sea. The primary difference between the two lies in the number of dashes and the areas they encompass:

Nine-Dash Line: The nine-dash line is the most commonly referenced demarcation. It encompasses a large area of the South China Sea, covering the Paracel Islands, Spratly Islands, and various other features. This claim is based on a map issued by the Republic of China government in 1947, which showed eleven dashes. Two dashes in the Gulf of Tonkin were later removed, resulting in the nine-dash line commonly referred to today.
Twelve-Dash Line: The twelve-dash line includes the same areas as the nine-dash line, but adds three more dashes to the north in the East China Sea, encompassing the Diaoyu Islands (known as Senkaku Islands in Japan). The twelve-dash line was used in maps issued by China in 1953 and afterwards.

The disputed islands between China and the Philippines in the South China Sea fall within what is commonly referred to as the “nine-dash line.” The “nine-dash line” is a demarcation line used by the People’s Republic of China (and previously, the Republic of China) to mark its claims over much of the South China Sea.

The disputes primarily concern areas around the Spratly Islands and Scarborough Shoal. Both of these areas are claimed by China and the Philippines, among other countries. China’s claims, marked by the “nine-dash line,” have been a source of ongoing tension and dispute. The Second Thomas Shoal, known as Ayungin Shoal in the Philippines and Ren’ai Reef in China, is within the “nine-dash line.”

The South China Sea is approximately 3.5 million square kilometers. The area within the Nine-Dash Line is is about 2.1 million square kilometers.

In 2016, an arbitration tribunal under the United Nations Convention on the Law of the Sea (UNCLOS) based on the concept of Exclusive Economic Zone (EEZ) ruled in favor of the Philippines in a case against China’s claims in the South China Sea. The Tribunal decision does not consider the sovereignty right founded on historical evidence. The EEZ is an area beyond and adjacent to a coastal State’s territorial sea to a limit of 200 nautical miles from the baseline. Within this zone, the coastal State may exercise sovereign rights over exploration, exploitation, conservation, and management of natural resources and other economic activities, such as the production of wind or tidal power.

The United Nations Law of the Sea (UNCLOS) was adopted in 1982 but was not effective until 1994, 35 years after the Nine-Dash Line was drawn, and does not alter China’s historical claims.

Professor Anthony Carty, in his recent interview video titled Game of Bluff: Renowned scholar confronts Western ‘neutrality’ on the South China Sea, dives into the historical complexities of conflicts in the South China Sea, analyzing the perspectives of the United States, UK, and France towards China.

The roots of the dispute

The controversy surrounding the South China Sea can be traced back to the early 20th century, particularly the actions of colonial powers like France and Britain. According to Professor Carty, the French decision to disturb Chinese ownership of the South China Sea islands in the 1930s marked a significant turning point. The French, motivated by imperial ambitions and the desire to counter Japanese expansion, seized islands without proper consent from their foreign ministry. This set a precedent that would complicate territorial claims for decades to come.

Carty’s research reveals that both British and French legal advisors consistently recognized the islands as Chinese territory. However, political convenience often led these nations to adopt a neutral public stance, particularly in the face of American pressure. This contradiction between public declarations and internal assessments has created a murky legal landscape that continues to fuel tensions today. The United States has played a pivotal role in shaping the narrative around the South China Sea. Initially, the U.S. maintained a neutral position regarding territorial claims. However, post-World War II, the U.S. shifted its stance, aiming to contain China’s influence in the region. This strategic pivot has led to a series of complex legal and diplomatic maneuvers, including the controversial San Francisco Treaty, which left many territorial questions unresolved.

Carty highlights that the U.S. has historically prioritized realpolitik over international law, often disregarding legal principles in favor of strategic interests. This approach has contributed to the ongoing instability in East Asia, as unresolved territorial disputes continue to fester. The reality is the United States of America has neither signed nor ratified UNCLOS.

Historical evidences for Chinese sovereignty

The following summaries of events are evidence collectively contribute to the argument for Chinese sovereignty over the South China Sea:

The Nine-Dash Line has historical roots dating back to ancient history, with claims established during the Pre-Qin and Han dynasties.
In 1887, China and France signed an agreement recognizing China’s sovereignty over the islands in the South China Sea
French legal advisors in the 1930s recognized that the Paracel Islands and Spratly Islands were Chinese territory, despite political decisions to claim them for France.
A memorandum from the British government in 1974 confirmed that the Spratly and Paracel Islands were recognized as Chinese territory, which was endorsed by the British cabinet.
The prominent French foreign minister, Aristide Briand, was aware of the legal advice stating that the islands were Chinese but chose to ignore it for political convenience.
Arthur Henderson, the British Foreign Secretary expressed horror at the French seizing the islands, stating that they were taking advantage of China’s weakness during a time of civil strife and Japanese aggression.
Wellington Koo, a distinguished Chinese international lawyer, wrote memoranda in French asserting that the islands were Chinese, which were acknowledged as correct by French legal advisors.
Records from the U.S. State Department in the 1950s indicated that the Philippines had no legal claim to the islands, reinforcing the notion that the islands were not theirs.
Legal files from the French Ministry of Foreign Affairs from 1974 to 1979 denounced Filipino claims to the islands, supporting the view that these claims were unfounded.
International law recognizes the activities of a nation’s citizens (like Chinese fishermen) as attaching sovereignty to their state, which supports China’s historical presence in the region.
The British and Americans historically claimed sovereignty over islands based on the presence of their nationals, which aligns with China’s historical fishing activities in the South China Sea.
A consensus emerged among British and French international lawyers over the years that the islands were Chinese, as documented in various archival records.

Rosario Manalo

The former Philippine ambassador, emphasized several key points regarding the Philippines’ relationship with the United Nations Convention on the Law of the Sea (UNCLOS):

Opting Out of Compulsory Arbitration: Manalo highlighted that when the Philippines ratified UNCLOS, it chose to opt out of the compulsory arbitration provision. This decision means that the Philippines cannot invoke compulsory arbitration to resolve disputes related to maritime claims.
Mutual Decision with China: She pointed out that China also opted out of the same provision, which results in both countries being unable to seek compulsory arbitration under UNCLOS.
Voluntary Arbitration under the UN Charter: Manalo noted that while the Philippines wanted to pursue arbitration, China’s reluctance meant that any arbitration would have to be voluntary. This creates a challenge, as one party cannot be forced to participate.
Establishment of an Arbitration Panel: She criticized the establishment of a Philippine arbitration panel, suggesting that it was not a true arbitration panel but rather a selection of individuals who might favor the Philippines’ position, raising concerns about impartiality.
International Attention: Despite the limitations of the arbitration process, Manalo acknowledged that the decision to pursue arbitration has brought international attention to the Philippines’ claims in the South China Sea, providing a platform to assert its position.
Need for New Processes: She suggested that a new process for settling disputes might be necessary, advocating for bilateral negotiations between the Philippines and China without external interference unless invited.

Overall, Manalo’s insights reflect a nuanced understanding of the complexities surrounding the Philippines’ maritime claims and the implications of international law in this context.