Revisiting China’s Rationale for Its South China Sea Claims

China’s assertions of ownership over disputed territories in the South China Sea and its refusal to recognize international law in maritime dispute settlements are the centerpiece of Beijing’s strategic defense initiatives against other claimant countries in the region and the United States. In its May 2009 notes verbales submissions to the UN Secretary-General, China claimed “it has undisputable sovereignty and jurisdiction over its islands and adjacent waters as well as seabed and subsoil thereof in the South China Sea,” and that as titleholder, it “has the right to decide whether, when and how to utilize these island chains and natural resources therein, to make and maintain physical presence there, and to install military and non-military facilities for the purpose of self-defense and/or protection of Chinese fishing and other economic and non-economic activities.” However, international legal experts and historians have examined the historical evidence behind China’s claims and found it insufficient and untenable. They have repudiated China’s historic rights claims as invalid and its sovereignty claims based on the nine-dash line map as illegal. 

Beijing’s aggressive expansionism in the South China Sea, which includes claiming more than 80 percent of the South China Sea since 2013, is dictated largely by its economic dependence on the main trade routes along the Strait of Malacca, as 60 percent of its trade travels by sea. This puts neighboring littoral states’ access to fishing and energy resources within their exclusive economic zones (EEZs) at risk, as well as freedom of navigation (FON) for countries plying their trade on sea routes that overlap China’s territorial claims, and freedom of overflight for foreign military and security operations in the region. 

South China Sea Disputes

Competing ownership claims over groups of islands in the South China Sea have dragged on for decades, with no apparent resolution in sight. Some analysts argue for maintaining that status quo as it seems to provide the best chance to avoid a potential escalation of conflict in the region. However, with China’s increasingly aggressive behavior fueled by its increasing military prowess, others argue for strengthening the military capabilities of other claimant countries (either by expanding their military infrastructures or by entering security alliances with other countries) to deter China. Still others argue for joint ventures in economic development and maritime resource explorations and for robust intratrade activities in the Indo-Pacific region. With freedom of navigation and safe passage for trade and the maritime rights of nations on the line, many experts believe the South China Sea could become the next Persian Gulf in terms of maritime and security importance. 

China has been in territorial disputes with regional littoral states since the 1950s, including: 

• With Vietnam over the Paracel Islands, currently occupied by China
• With Taiwan, Vietnam, the Philippines, Malaysia, and Brunei over the Spratly Islands, currently occupied in part by all these countries except Brunei
• With Taiwan and the Philippines over Scarborough Shoal, controlled since 2012 by China
• With Japan and Taiwan over the Senkaku Islands in the East China Sea, currently being administered by Japan

In addition, China and the United States differ over the interpretation of freedom of navigation and the right to regulate foreign military activities in the South China Sea, with the United States contending that while the U.N. Convention on the Law of the Sea (UNCLOS) has “established EEZs as a feature of international law and gives littoral states the right to regulate economic activities (such as fishing and oil exploration within their EEZs), it does not give states the right to regulate foreign military operations in the parts of their EEZs beyond their 12-nautical-mile international waters.” However, China insists it can regulate both economic and foreign military operations within its claimed territories. These differing interpretations are at the core of incidents between China and the United States in international waters and airspace dating back to 2001. 

Historic Rights and Sovereignty Claims

Chinese officials and scholars trace China’s maritime claims back to the Qin and Han dynasties (circa 221 BC–220 AD) and claim its maritime boundary was established during the Qing dynasty (circa 1644–911): “China has maintained her sovereignty over these island chains by ways of discovery, naming, mapping, patrol and control, public and private use, administrative allocation of jurisdiction, and other manifestations of authority throughout history.”¹ 

However, other countries in the region are able to present historical evidence to support their own claims. Vietnam has maps claiming historical sovereignty in the Paracel Islands going back to the 17th century. The Philippines has produced old maps supporting its ownership of Scarborough Shoal, which China has claimed: the Carte Hydrographica y Chorographica de las Islas Filipinas, a map dating to 1734 and published in Madrid in 1808, includes Scarborough Shoal (known as Bajo de Masinloc) as part of Philippine territory. In addition, a topographic map drawn in 1820 shows Bajo Scarburo as part of Zambales, a Philippine province.

Professor Mohan Malik of the Asia-Pacific Center for Security Studies at the University of Hawaii says China’s claims are historical fiction: “Since the end of the Second World War, China has been redrawing its maps, redefining borders, manufacturing historical evidence, using force to create new territorial realities, renaming islands, and seeking to impose its version of history on the waters of the region.” But with the changing world order, Malik argues, China’s claims based on ancient maritime traditions are irrelevant. 

Historically, the South China Sea has been used by everyone as a transoceanic sea route. The high seas were viewed as a global common, and international waterways were open to traders, seafarers, and fishermen plying their trades along the South China Sea routes. According to Professor Malik, the South China Sea’s busy maritime traffic made possible the rise and fall of imperial powers, from the Chinese to the Mongols who dominated the seas during the early centuries to the Europeans who actively engaged in trading during medieval times. But the modern period brought about a world order of nation-states, with clearly delineated national boundaries, that supplanted a world order of empires and undemarcated jurisdictions. Malik contends that China seems stuck in historical traditions characterized by imperial territorial encroachments.

Chinese officials insist the nation’s sovereignty claims over “territories that belong to China since ancient times” precede enactment of UNCLOS, hence, the law does not apply: “history trumps law.” However, in their legal analysis of China’s historic rights claims, international law professors Florian and Pierre-Marie Dupuy argue that mere reliance on historical evidence as invoked by China is insufficient to establish sovereignty over territories in the South China Sea: “No international court or tribunal would agree to base its decision on arguments and contested evidence to the effect that China was the first country (several hundred years ago) to explore the South China Sea and discover, name, and administer its islands.” The professors further argue that although historical factors should be considered, “their relevance must be limited to establishing whether a given state has exercised and still exercises authority a` titre souverain over a defined area in an effective and continuing manner, and whether such exercise of authority has been accompanied by acquiescence by the third states concerned.” They contend none of these elements has been established by China.

The Nine-Dash Line Map 

The nine-dash line map, which has been presented by Beijing as evidence of its legal claim of 80 percent of the South China Sea, was first published in 1948 by the Republic of China’s Interior Ministry in Taiwan. The map encompasses 2,000,000 square kilometers of maritime space equivalent to about 22 percent of China’s land area and comes very close to the coastlines of neighboring littoral states, including the Philippines, Vietnam, Malaysia, Brunei, Darussalam, and Indonesia’s Riau Islands.

Legal experts have argued that since cartographic materials do not constitute titles in international law, the map is of no legal value: “The principle that emerges from international jurisprudence and doctrinal discussions is that cartographic materials do not by themselves have any legal value.” 

Professors Pierre Marie and Florian Dupuy also argue that China’s 2009 and 2011 Declarations to the UN did not meet at least two central requirements applied by international courts in deciding whether maps can have a probative value: (1) geographical accuracy and reliability, and (2) neutrality in relation to the dispute and the parties involved. Therefore, 

• The nine-dash line map cannot be used as a reliable tool because it does not clearly provide the limits of China’s maritime sovereignty. According to maritime scholars, “not only is the meaning of the line indeterminate, but the line is drawn in the most inaccurate possible way: the thickness of the line, its lack of precision (due in particular, to the empty spaces between the nine dashes), and the absence of geographical coordinates make it impossible to determine the precise area enclosed by it.” 
• An international court can consider a map of legal value only if it “constitutes the true and accurate manifestation of the will of a competent national authority or if it reflects an agreement between the states potentially concerned (in this case, China and its neighbors).” Since China’s nine-dash line map was not a product of a consensual agreement between two parties, the professors concluded it was not created and established by an unbiased, neutral party. 

The U.S. State Department also has concluded that China’s nine-dash line map is inconsistent with international law: “If the dashes on Chinese maps are intended to indicate national boundary lines, then those lines would not have a proper legal basis under the law of the sea. Under international law, maritime boundaries are created by agreement between neighboring States; one country may not unilaterally establish a maritime boundary with another country.” 

Challenges

China’s claims, based solely on historic rights and ancient maritime traditions, are being challenged by other claimant countries, including the Philippines, Vietnam, Malaysia, and Brunei, as untenable, citing instead the laws of the sea as enunciated by UNCLOS—to which China is a signatory—as the rightful legal bases for the settlement of maritime disputes. While the U.S. is not a signatory to the UNCLOS, it accepts certain provisions of the treaty—such as those relating to navigation and overflight —which the U.S. deems consistent with customary international law to which it subscribes, and acts accordingly. Without a rules-based approach for settling maritime disputes in the South China Sea, China’s illegal posturing and aggressive actions threaten regional stability and global interdependence that could lead to a wider conflict. This article is an offshoot of the author's previous article, “Chinese Lawfare in the South China Sea: A Threat to Global Interdependence and Regional Stability,” published in the Journal of Political Risk in July 2022.