Drawing the U-Shaped Line

Sovereignty and Development in the South China Sea Islands after the Second World War

The earliest archival files examined in this article were written in 1946, which marked a continuance of the scramble for the South China Sea islands. Japan’s wartime occupation of the archipelagos had only suspended a prior contest in the 1930s between France, Japan, and the ROC (Granados, 2008: 132–40; Samuels, 1982: 55–64). Immediately after the war, the ROC was determined to “reassert” and “protect” its sovereignty over these islands from foreign “infringement.” On September 25, 1946, representatives of the Ministry of Foreign Affairs, Ministry of the Interior, Ministry of National Defense, and ROC Navy General Headquarters 海軍總司令部 (NHQ) convened in the Ministry of the Interior to resolve several issues pertaining to the South China Sea islands (MOFA, file series 019.3/0012, files 097 and 098). The minutes listed each issue and the resolution agreed upon. The first topic, the most significant, determined the scope of what the ROC would claim in the South China Sea:

Resolved matters:

1. The case of how to delimit the scope of what is to be received [from Japan] for the purpose of reclaiming [lit., “receiving”] each of the islands in the South China Sea.

Resolution: As according to the scope shown in the Ministry of the Interior’s copy of the Location Sketch Map of the South China Sea Islands 南海諸島位置略圖. After the Executive Yuan has checked and approved [the scope], it will order the Guangdong provincial government to comply [and carry it out]. (MOFA, file series 019.3/0012, file 097)

決議事項：1. 接收南海各島應如何劃定接收範圍案。決議：依照内政部擬製之「南海諸島位置略圖」所示範圍呈由。行政院核定令廣東省政府遵照。

The dual use of the verb “to receive” 接收 reflected the ROC’s view that the islands were originally theirs. It was “reclaiming” them from Japan, which had recently surrendered.

This passage clearly conveys the ROC government’s view of the U-shaped line. It referred solely and directly to the Location Sketch Map of the South China Sea Islands—the 1946 U-shaped line map that led to the official version the following year (Map 2 in the Appendix)—when demarcating the area that was to be under Chinese sovereignty. ⁸ However, all of the area within the U-shaped line was not to be ROC territory. The above passage merely defined the islands to be reclaimed: “the scope of what is to be received for the purpose of receiving each of the islands of the South China Sea” (italics added) (“接收南海各島應如何劃定接收範圍案”). Mention of matters pertaining to the waters around the islands is absent. The remaining six resolutions of the conference concerned other details about the islands, such as the physical expression of Chinese sovereignty or the approval of translations of the names of these islands (MOFA, file series 019.3/0012, files 097 and 098). The U-shaped line, in other words, was created solely to delineate China’s sovereignty over the land of the islands and other features.

This resolution was adopted in late 1946, when ROC Commanding Officer Lin Zun and Captain Yao Ruyu led several naval expeditions to formally “reclaim” the South China Sea islands from the Japanese. Despite repeated delays in mid-November due to stormy weather, the main islands were secured the following month. ROC troops landed on Woody Island of the Paracels on November 28, 1946, and Itu Aba Island of the Spratlys on December 12, 1946 (MHTO, file series 0035/061.8/3030, files 002/001/0002 and 002/003/0002; MOI, file series 0036/E41502/1, file 0005/007/0001; MHTO, file series 0036/002.2/4022, file 001/001/0005).

These expeditions further constituted the basis for the official U-shaped line of 1947. The “recapture” of these islands led to government discussions about the need for a clear expression and protection of sovereignty over the islands. Situation reports—surveys of the islands describing their geographic coordinates, topography, vegetation, resources, personnel, buildings, histories, and almost always recommendations for future actions—began to call for increased garrisons and construction on the islands. For instance, the Report on the Reconnaissance of the Paracel Islands in the South China Sea 南海西沙群島勘察報告書, written by the ROC Air Force General Headquarters 空軍總司令部 and issued on December 25, 1946, recommended that more naval personnel be dispatched to safeguard the islands (MHTO, file series 0035/944/1060, file 001/001/0007). On February 4, 1947, the Report on the Reconnaissance of the Spratly Islands in the South China Sea 南海南沙群島勘察報告書 noted that “the Chinese navy has already sent a platoon of soldiers to garrison the islands and set up weather observation and radio stations to prevent foreigners from coveting, invading, and occupying the islands” (MHTO, file series 0035/944/1060, file 001/002/0007). It recommended building a 1,200 meter air strip on Itu Aba Island and envisioned turning the archipelago into a string of “island bases in the South China Sea, akin to American bases in the Pacific Ocean” (MHTO, file series 0035/944/1060, file 001/002/0007).

The ROC government soon held plenary meetings to discuss plans to develop the islands in order to “safeguard” national defense. The Ministry of National Defense sent a report— File on Increasing Defense and Building Facilities in the Paracel Islands for Ensuring the Protection of Sovereignty [over the Islands] and the Strengthening of National Defense 加強建設西沙群島力保主權而固國防案—of one such meeting to the Executive Yuan on June 14, 1947. It recommended increasing the ROC’s military presence in the South China Sea islands by garrisoning troops “wherever possible in the archipelagos”; protecting fishermen who “come from Hainan Island and go to the islands” to fish; “vigorously constructing” lighthouses, weather stations, and radio stations; improving food and water equipment; deciding on the islands’ system of governance; investigating several aspects of the islands such as soil quality, weather, marine resources, and governance in order to aid the development of facilities there; and compiling research about the islands to expound Chinese sovereign rights and impress their importance on the Chinese population (MHTO, file series 0035/061.8/3030, files 005/012/0009 to 0011). The ROC supported the garrisoning and development of the South China Sea islands in order to show the world that they were theirs, actions that led to the official promulgation of the U-shaped line.

These files again strongly support the island attribution line. They focus almost exclusively on matters pertaining to the islands’ land territories. While the plans for development were never completed because of the Chinese Civil War (1946–1950), the ROC nevertheless strove to assert ownership over the land territories of the archipelagos for the explicit purpose of “reclaiming,” demonstrating, and protecting its sovereignty from foreigners (Granados, 2006a: 173–74). The same cannot be said for the waters around the islands. Neither report made any mention of plans for naval protection over a large special waters zone of any kind. There were only two, and rare, exceptions to the absence of maritime affairs in the archival files. The first was the establishment of naval patrols in order to safeguard supplies to troops stationed on the islands, as distinct from those established to protect a waters zone (MHTO, file series 0035/061.8/3030, file 005/012/0010). These patrols simply were meant to escort supply ships. The second exception was the protection of Chinese fishermen. For instance, as the File on Increasing Defense and Building Facilities in the Paracel Islands advocated, the ROC government was to “implement immigration [to the islands] for fishermen who regularly and seasonally travel from Hainan to the Paracel and Spratly archipelagos to fish, and provide greater protection of their fishing permits” (MHTO, file series 0035/061.8/3030, file 005/012/0010). To “provide greater protection of their fishing permits,” the ROC navy was to ensure that no one challenged the fishermen’s activities.

Although such reports did not specify the exact scope of fishing waters to be guarded by the ROC navy, only “fishermen who went to the Paracel and Spratly Islands from Hainan to catch fish” were to be protected (“對於我國 . . . 來往西南沙群島捕水產之瓊州漁民應加保護獎助.” Qiongzhou 瓊州 was the old term for Hainan Island). This passage, coupled with the ROC’s focus on the islands’ land territory, strongly indicates that Chinese fishermen stayed close to the islands and did not routinely venture into the vastness of the South China Sea. This interpretation fits the ROC’s contemporary conception of waters zones. At the Hague Codification Conference of 1930, the last international meeting to discuss the standardization of the scope of territorial waters before the creation of the U-shaped line maps, the ROC supported a three nautical mile territorial waters zone and a twelve nautical mile contiguous waters zone beyond it (Koh, 1987: 7–8). The ROC government officially implemented the former zone in 1931, the latter in 1934, and allowed fishing within both despite the conference having never reached a consensus (Chiu, 1975: 38–41; Granados, 2006a: 167). It did not support any other waters zone beyond these two until the concept of the continental shelf zone was first discussed internationally in the UN Geneva Convention of 1958. That the scope of protection of fishermen was not specified in any archival document, especially those focused on increasing the ROC’s defense and development of the islands, compromises any argument that the ROC at this time held a historic rights waters view.

It is doubtful that the minutes of the September 1946 conference, the summaries of other meetings convened on the issue, and the situation reports in the ROC archival collections would leave out reference to a special waters zone as massive as the U-shaped line, if one existed. Two express purposes of these documents and meetings were, first, to define the geographical scope of what was to be Chinese, and second, to specify what areas were to be developed and how, with the deliberate aim of asserting and “protecting” Chinese sovereignty. The September 1946 conference, furthermore, eliminates another possibility: that a historic rights waters zone could have emanated from the mainland and not from the South China Sea islands, thus explaining the absence of references to special waters zones in the archival files. As the September 1946 conference summary showed, the ROC purposely created and used the U-shaped line to encompass all matters pertaining to the islands. One cannot dissociate a historic rights waters zone from the islands, since the waters were represented by the line, whose existence hinged on those insular features. Any historic maritime zone as delineated by the U-shaped line must emanate from the South China Sea islands, as must any discussion of the idea. Even authors who support a historic rights claim, such as Fu and Huang, indirectly admit this much, as they unfailingly assert that the line represented and enforced a waters zone in addition to showing Chinese sovereignty over the islands (Fu, 1995: 204–10; Huang, 2011).

Similarly, plans to develop marine resources shortly after the genesis of the U-shaped line also focused exclusively on the islands. In March 1950, the Hainan Fisheries Authority submitted a report to the NHQ, titled The Hainan Fisheries Authority’s Pilot Project on the Development of Marine Resources in the Paracel Archipelago 海南特區水產管理局西沙群島水產開發試驗計劃. It proposed four objectives in expanding the exploitation of resources in the waters around the islands. The first three were to process useful marine fauna; relieve unemployed fishermen by resuming development of marine resources; and “clearly understand” the Paracel and Spratly archipelagos and plan their future development. The fourth “objective” comprised four points, some redundantly listed: increase revenue, cultivate marine resources, improve the islands’ infrastructure, ⁹ and carry forward the Hainan Fisheries Authority’s business plans for the islands. It described the funds and equipment required for the proposal, conditions of investment, and plans for radio communication between fishermen and the islands (MHTO, file series 0035/061.8/3030, files 007/013/0011 to 0014). The proposal did not mention protection of Chinese fishermen nor a special waters zone to be enforced by the ROC navy. The first two objectives were silent on the specific area of fishing. In contrast, the third and fourth objectives solely and repeatedly referred to the development of the islands’ land territories so as to support fishing nearby. The project merely envisioned an intensification, not an expansion in geographic scope, of the exploitation of marine resources.

Granted, nearly all ROC naval forces stationed on the South China Sea islands had been transferred to Taiwan by June 1949, to defend it against an expected PRC invasion. Yet, a small military presence remained on the islands until May 1950, two months after the Pilot Project was drafted (Granados, 2006a: 160, 162). This decrease cannot account for the absence of well-defined limits of maritime jurisdiction and protection in the plan. On April 12, 1950, the NHQ sent a telegram to the Hainan Fisheries Authority suggesting modifications to the Pilot Project. One proposed that five percent of “profits” go toward the welfare of naval units that provide assistance to the islands as well as “rewards” for garrison troops (“盈利部分提百分之五應改爲海軍協助單位福利金及駐島官兵犒賞費”) (MHTO, file series 0035/061.8/3030, files 007/014/0002 to 0003). The source of these “profits,” although unspecified, was likely the development of the islands, given the telegram’s purpose of providing modifications to the March plan. The ROC evidently remained confident in the future development of the islands and the military’s ability to protect them.

ROC diplomatic protests made after the release of the U-shaped line further support the islands attribution argument. The ROC only protested against “infringements” of sovereignty over the islands’ land territories, not its waters. One example provides a telling distinction between the islands’ land and maritime jurisdictions and their importance to the ROC government. On April 13, 1949, ROC ambassador Chen Chih-Ping raised with Felino Neri, the Filipino undersecretary of foreign affairs, the issue of newspaper articles that stated that the Filipino government planned to send Commodore Jose Andrada to inspect Itu Aba Island. One article in particular reported that “some cabinet members suggested that their people be induced to settle there [on Itu Aba] preparatory to making a claim for the annexation of this group to the Philippines, if necessary, as a security measure.” Chen requested confirmation of the veracity of these statements and emphasized that “Taiping [i.e., Itu Aba] Island is the territory of the Republic of China.” Neri’s reply on May 11 reassured Chen that there was no cause for worry: “In the meeting referred to, the Cabinet simply discussed the need for affording greater protection to Filipino fishermen who are reportedly operating in the waters surrounding Itu Aba” (MOFA, file series 019.3/013, files 038 and 039).

Both Chen’s and Neri’s letters indicated that the islands’ land territories were the main concern of the ROC government. Chen worried that the Filipino cabinet had authorized an inspection of Itu Aba Island and discussed the settlement of Filipino fishermen there, thus “infringing” on the ROC’s sovereignty. Neri recognized Chen’s concern, and through the word “simply” denied the validity of the newspaper reports. Neri, however, clearly thought the presence of Filipino fishermen “operating in the waters surrounding Itu Aba Island”—well within the limit delineated by the U-shaped line—was not an issue. He never mentioned maritime jurisdiction, which presumably he considered a relatively trivial matter.

Chen never replied to Neri’s response, which suggests that the Filipino explanation satisfied the ROC. The ROC did not issue any diplomatic protests against the Philippines involving sovereignty issues in the South China Sea region until late May 1956, after a Filipino citizen, Thomas Cloma, informally proclaimed the formation of Kalayaan, or “Freedomland,” over some of the Spratly Islands to the Filipino and world press on May 15 (Samuels, 1982: 82). ¹⁰ The ROC responded by sending three expeditions to reclaim the Spratly Islands from June 1 to September 24, 1956—ROC garrisons on the islands earlier had been recalled to defend against an anticipated Communist invasion of Taiwan (Samuels, 1982: 84). In short, for the ROC, it was the islands that were the key aspect of the South China Sea archipelagos, not the exclusion of foreign fishermen from the surrounding waters. The ROC did not consider the waters of the U-shaped line as providing special rights.

Like Freedomland, the “Kingdom of Humanity” was also a foreign threat to “Chinese sovereignty” over the islands. Although private American citizen Morton Meads’ attempt to establish an independent country over part of the Spratlys was seen as bizarre or comical by most of the international community—Filipino naval and air searches for the kingdom using coordinates provided by Meads proved fruitless—the ROC treated the affair seriously (MOFA, file series 019.3/0003, files 045 to 046). On July 9, 1955, Chow Shu-Kai, ROC chargé d’affaires ad interim in Manila, notified Filipino vice president Carlos Garcia, who also was serving as the Filipino secretary of foreign affairs, that the ROC was

conducting [an] investigation in the waters around the Spratley Islands [sic] in connection with alleged violation of Chinese territory by the so called “Kingdom of Humanity.”

According to information emanating from the “Consul” in Manila of said “Kingdom” [i.e., Meads ¹¹ ], the “Kingdom’s” territory appears to be so delineated as to include the Spratley Island Group, which constitutes part of the territory of the Republic of China. The Chinese Government has therefore initiated action to conduct [an] investigation in said area with a view of determining whether infringement on Chinese territorial rights has been committed by the said “Kingdom.” It would be appreciated if Your Excellency would kindly acquaint pertinent authorities of the Philippine Government with this effect. (MOFA, file series 019.3/0003, file 077)

This statement did not constitute a direct diplomatic protest to Manila, as Meads was acting on his own. Chow was simply informing Garcia of Chinese naval activity in the Spratlys as a result of information on Meads that it received from the Philippines. It may, however, have been an indirect warning, as former Filipino senator Camilo Osías openly believed that the Kingdom existed and the Philippines should establish diplomatic ties with it (MOFA, file series 019.3/0003, file 046). Osías was the only significant politician in his country to take Meads’ claim seriously. Chow may have aimed to dissuade the Philippines from annexing the Kingdom by reiterating China’s claim to the Spratlys. In any case, the focus again was solely on the islands’ land territory. While the ROC’s investigation was conducted in the waters surrounding the islands, its purposes were to ensure that its sovereignty on the islands was not infringed and to prevent further incursions by foreigners.

Japan’s Administration of the South China Sea Islands and Their Postwar Transfer to China

The post–Second World War transfer of sovereignty over the islands from Japan to China presents certain possibilities that could undermine the islands attribution line argument. ¹² By March 30, 1939, Japan had militarily occupied the Pratas, Paracel, and Spratly Islands. The next day, it formally proclaimed the creation of the Shinnan Guntō 新南群島 (New South Archipelago), an administrative area covering a portion of the Spratlys and incorporated under Taiwan province (Granados, 2008: 138). ROC archival files on the South China Sea islands include a map of this administration. Its boundaries were solid and encompassed a significant area of water. Its seven corners possessed specific geographic coordinates, contained within the range of 7–12° N and 111–117° E (MOFA, file series 019.3/0012, file 066). ¹³ Plausibly, the boundary encompassed the Shinnan Guntō’s waters, indicating that the zone conferred certain exclusive maritime rights. However, no written document directly verifies this assumption.

Nevertheless, irrespective of the nature of the Shinnan Guntō’s boundaries, the postwar transfer of Japan’s wartime administration of the islands to China could not have contributed to a historic rights waters zone as delineated by the U-shaped line. If the Shinnan Guntō’s boundaries simply denoted an islands attribution line, there would be no waters to hand over to the ROC in the first place when China reacquired Taiwan province after the war. If the Shinnan Guntō’s boundaries did denote a waters zone, this was lost in the postwar transfer to China. The Shinnan Guntō factored into the formation of the U-shaped line because of the islands it encompassed, not because it conferred a delineated sea zone. As a telegram order that the Ministry of Foreign Affairs sent to the NHQ on August 5, 1946, indicated, the ROC was simply preparing to take back the islands of the Shinnan Guntō it thought were originally its own. It sought to clarify whether they were the same as those of Tizard Bank, or the Tuansha Islands 團沙群島 (MOFA, file series 019.3/0012, file 014). ¹⁴ In December 1946, the ROC dropped the Tuansha appellation and subsumed the area within the Nansha, or Spratly archipelago (MOFA, file series 019.3/0013, file 030).

The report resulting from the telegram listed the islands individually and gave general descriptions of them, with no mention of any waters zone. It concluded that the Tuansha constituted only one part of the Shinnan Guntō, meaning the two were not identical (MOFA, file series 019.3/0012, files 014, 016 to 019). Besides the ROC’s sole focus on the islands, these files show that it was not interested in inheriting the Shinnan Guntō administration. Rather, the ROC sought to restore what it thought was the prewar administration of the Tuansha by reclaiming the Shinnan Guntō islands that coincided with the former. These files undercut any argument that the ROC inherited the waters delineated by the boundaries of the Shinnan Guntō.

The ROC’s main goal of restoring the prewar Tuansha administration strongly indicates the U-shaped line’s islands attribution character in another way. No official Chinese maritime boundaries delineating sovereignty over waters existed in the islands region before the Second World War, including the Tuansha administration and the claims of prior dynasties it was based on. ¹⁵ Consequently, China had no historic rights waters to inherit after the war. Precursor maps of the U-shaped line existed from the 1910s to 1930s, but the ROC government never officially endorsed them for release. Hu Junjie, a Chinese cartographer, drew the first such map in 1914, which included only the Pratas and Paracel islands. Maps of the region largely continued this pattern until the mid-1930s. In 1935, the ROC Land and Water Maps Inspection Committee 水陸地圖審查委員會 created the Map of Chinese Islands in the South China Sea 中國南海各島嶼. It placed the southernmost edge of China’s maritime boundary at 4° north latitude, thus incorporating the Spratly Islands and James Shoal. Bai Meichu, another prominent Chinese geographer, drew the last notable map on the eve of the Sino-Japanese War in 1936, the Map of Chinese Domain in the South China Sea 海疆南展後之中國全圖. It did not include a boundary line (Zou, 2007: 88–89).

Records from the Qing dynasty indicate that China did not claim or exercise a long-standing dominance of the waters in the center of the South China Sea, as would be needed to substantiate a historic rights waters zone. ¹⁶ Mentions of the islands were sparse, brief, and merely demonstrated that China was aware of their existence. An example is Chen Lunjiong’s Records of Sights and Sounds of the Maritime Countries 海國聞見錄, an official compendium of geographies, locations, and maritime routes to many foreign kingdoms. Completed in 1730, it was the first Qing work to mention the islands:

[Sailing] by oneself in the Greater Qizhou Sea 七州大洋: ¹⁷ The beginning of the sea lies off [of Hainan Island]. The waters here are lively and swing back and forth. There is a ridge of mountains marking the start of the Qizhou Sea 七州洋. ¹⁸ Sail with the correct compass bearings and with strong yet smooth winds. Six to seven days are needed for one to cross [the Qizhou Sea], after which one will be able to spot Tiebiluo 呫嗶囉 [present-day Cham Islands], which lies off the coast of Guangnan 廣南 [Vietnam]. To the east, one will encounter 犯 the Wanli Changsha 萬里長沙 [the Paracels] and Qianli Shitang 千里石塘 [the Spratlys]. To the west are currents that flow into Guangnan Bay [the Gulf of Tonkin]. Without a western wind, one cannot leave this area. (Chen, 1984: 120)

Chen simply described the islands’ locations, their use as sea-route landmarks, and the directions needed to sail there. The islands, however, were not intended to be traveled to. Chen noted only that if one strayed east from his described route, these islands would be “encountered.” The corresponding Chinese character, 犯 (fan), normally denotes “illegality,” “trespassing,” and “violating,” indicating that the Qing regarded the islands as locations to be avoided. All subsequent Qing texts that mentioned the South China Sea islands repeated Chen’s focus on description, such as Yan Ruyou’s Essentials of Maritime Defense 洋防輯要 of 1838 and Wei Yuan’s Illustrated Gazetteer of the Maritime Countries 海國圖志 of 1847 (Samuels, 1982: 40). There is no mention of dominance over the waters surrounding the islands.

Qing naval defense manuals and travel chronicles, far from considering these archipelagos as areas to be patrolled by the Qing navy, commonly warned sailors to stay away from them. For instance, Lu Kun and Deng Tingzhen’s Compendium on the Maritime Defense of Guangdong 廣東海防彙覽, completed in 1838, wrote of the “extreme danger” 極險 one would encounter when deviating into the area (Lu and Deng, 2009: 969). Yang Pingnan’s Maritime Records 海錄, written in 1844, was especially vivid:

Ships that stray into [the Wanli Changsha 萬里長沙, or Paracels] cannot return due to these floating sands. Many ships are destroyed here. Sailors who encounter this fate have no choice but to lie on wooden planks [i.e., the flotsam of their shipwreck] and spend many days floating toward the sands. . . . To the south of the Qizhou Sea is the Qianli Shitang 千里石塘 [the Spratlys]. Here, there are a great many terrible and furious waves. If ships stray into this area, they will be smashed to pieces. (Yang, 1984: 265–66)

Shallows, storms, and frequently changing winds and currents that can push boats toward the islands and submerged features characterize the area, prompting Yang to remark that ships that stray there cannot escape (United States National Geospatial Intelligence Agency, 2004: 3–14). Sailors had known of these dangers for centuries. As Granados and Samuels note, major trading routes avoided the hazardous center of the South China Sea (Granados, 2006b; Samuels, 1982: 23). The most used route hugged the coastline of southeast China and eastern Vietnam, down south to the coasts of Thailand, Indonesia, and Malaysia. This absence of historic domination over almost all of the South China Sea attenuates any claim to a transfer of sovereignty that could lead to a historic rights waters zone within the U-shaped line.

Physical Characteristics of the U-Shaped Line

Another topic that merits close examination concerns the appearance and physical characteristics of the U-shaped line in its three major manifestations: the 1946 and 1947 versions of the Location Sketch Map of the South China Sea Islands and the official 1947 Location Map of the South China Sea Islands, which was later publicly released in 1948 (see Maps 1, 2, and 3 in the Appendix). The way the line was drawn supports the conclusion that it was an islands attribution line, not a historic rights waters zone.

Chinese scholars often state that the U-shaped line was an equidistant marker between China and neighboring states. As Li Jinming and Li Dexia note, Wang Xiguang, an ROC official who helped formulate the U-shaped line, stated that “the dotted national boundary line was drawn as the median line between China and adjacent states” (Li and Li, 2003: 290). A line equidistant to the shores of countries claiming the same waters can suggest a maritime boundary. Such a line was one of many basic methods of compromise between competing spheres of maritime sovereignty at the time. Indeed, the distances between the southeasternmost Spratly Islands, the U-shaped line, and Borneo and Palawan Island, are roughly equidistant in the U-shaped line maps. However, this equidistance principle did not feature in most of the U-shaped line, such as between Macclesfield Bank and the Philippines and between the easternmost Spratlys and the southeastern coast of Vietnam (see Maps 1, 2, and 3 in the Appendix). In these cases, the distance from the U-shaped line to the nearest land feature was either much shorter or longer compared to that of the opposite side of the same section of the line. Hence, it is problematic to claim that the U-shaped line was a maritime boundary because of its employment of the equidistance principle.

Virtually all scholars of the South China Sea dispute, moreover, overlook another noteworthy feature. On all three maps of the U-shaped line, an inconspicuous section branches off from the main boundary line and sits between the southern tip of Palawan Island of the Philippines and northern Borneo (see Maps 1, 2, and 3 in the Appendix). ¹⁹ This section was attached to and marked identically with the same pattern as the rest of the boundary, using a series of dots, lines, and in the two 1947 maps, incomplete circles. What it denotes thus presumably held true for the rest of the U-shaped line.

This segment of the line clearly did not delineate a maritime boundary. It extended eastward into and past the Philippines’ border with northern Borneo, as defined in the Filipino constitution of 1935. According to the government of the Philippines, the nation’s boundaries stemmed from the “Philippine Treaty Limits,” based on three treaties: the Treaty of Paris between Spain and the United States of December 10, 1898; the Treaty of Washington between Spain and the United States of November 7, 1900, and the “Convention between the United States of America and Great Britain Delimiting the Boundary between the Philippine Archipelago and the State of North Borneo” of January 2, 1930. The last is the most recent and relevant treaty concerning the boundary between North Borneo and the Philippines (Bautista, 2011: 37–39). ²⁰

Granted, the boundary set by this treaty appeared to have been only an islands attribution line. It established “the line separating the islands belonging to the Philippine Archipelago on the one hand and the islands belonging to the State of North Borneo which is under British protection on the other” (Government of the Philippines, 1930). The treaty did not specify “waters” of any sort. Only in 1961 did the Filipino government officially declare that its territorial waters lay between its straight baselines and the boundaries set by the “Philippine Treaty Limits” (Government of the Philippines, 1961).

Nevertheless, if the boundary set by the 1930 convention had indicated only the islands of the Philippines and Borneo and not their waters, the same conclusion would hold. As Tommy Koh notes, for over a hundred years before the Second World War, Great Britain was a champion of the three nautical mile limit concept for territorial waters (Koh, 1987: 9). It constantly strove to maintain this range unless agreed otherwise in special arrangements with foreign states. Two months after the U.S.–Great Britain Convention of 1930, Britain reiterated this stance in the Hague Codification Conference (Koh, 1987: 7–8). This international conference was the first and last of its kind to address the scope of a nation’s waters before the creation of the U-shaped line maps. The segment of the U-shaped line in question, however, did not reflect such long-established maritime borders. According to the distance conversion scale provided by the three U-shaped line maps, the segment of the U-shaped line between British-held Borneo and the Philippines lay roughly 25 km, or 13.5 nm, from the nearest coast of either state, far past the three nautical mile mark (see Maps 1, 2, and 3 in the Appendix). Whether the Philippine Treaty Limits denoted a waters zone in 1946 and 1947 is inconsequential. In either scenario, this segment of the U-shaped line did not conform to any maritime boundary or principle previously recognized in the region, whether by the United States, Great Britain, or the Philippines.

In contrast, arguably the ROC drew this segment of the U-shaped line merely to specify where the land of the Philippines ended and that of Borneo began. They possessed islands that were close to each other, particularly the three visible in the U-shaped line maps: Balabac, Banggi, and Balambangan (see Maps 1, 2, and 3 in the Appendix). The U-shaped line correctly marked as Filipino the same islands established by the 1930 convention. This segment of the line, furthermore, does not extend longitudinally past the western half of the width of Palawan Island. Why it was cut short and not enclosed can best be explained by the ROC’s main preoccupation with denoting which islands were whose via the U-shaped line from China’s viewpoint. The digression of the line from the main U-shaped body was extended just enough to serve a useful purpose: to avoid confusion in the map. This argument again supports the islands attribution line. Carried over to the rest of the U-shaped line, this underlying intent would explain especially those parts that were equidistant from neighboring lands, such as between the South China Sea islands and Palawan and Borneo, where the two groups lay close to each other and had to be divided for demarcation purposes.

The 1945 Truman Proclamation and Continental Shelf Zones

It would be unconvincing to argue that the archival files did not mention a historic maritime zone around the islands simply because waters zones had not yet been internationally standardized and were seen as a natural extension of the land and hence did not merit mention. Although the Hague Codification Conference of 1930 did not produce an international standardization of territorial waters, countries nevertheless thereafter unilaterally specified maritime borders. On September 28, 1945, for instance, the United States proclaimed the “1945 US Presidential Proclamation No. 2667, Policy of the United States with Respect to the Natural Resources of the Subsoil of the Sea Bed and the Continental Shelf.” Also known as the Truman Proclamation of 1945, this document broke precedent in international law by unilaterally declaring an extended fisheries protection and continental shelf zone (Government of the United States of America, 1945). Several other countries followed suit, such as Saudi Arabia and Kuwait in 1949; Chile, Ecuador, and Peru in 1952; Israel in 1953; Iran in 1955; and Venezuela in 1956 (Suarez, 2008: 28–29). This trend led to a convention on continental shelves in the First United Nations Conference on the Law of the Sea, held in Geneva on April 29, 1958 (Suarez, 2008: 29). By no means were countries uninterested in defining the scope of their waters around the time of the creation of the U-shaped line.

The ROC was no exception. It officially announced the extent of its maritime boundaries in 1931 and 1934, before the creation of the U-shaped line. Yet, a historic rights waters zone as massive as the area within the U-shaped boundary would have broken precedent with the ROC’s existing borders and the whole world. The line was created at a time when the idea of continental shelves—never mind an even larger historic maritime zone—was still revolutionary in international law. If the concept of a historic maritime zone was what the ROC intended with the U-shaped line, it would not have overlooked the matter out of “insignificance,” given the sheer level of detail contained in the situation reports, plans for development, and conference summaries that defined the scope of the line.

Fu’s and Gao and Jia’s conclusion that the U-shaped line denoted historic rights waters precisely because it was the ROC’s own Truman Proclamation is, however, problematic (Fu, 1995: 204; Gao and Jia, 2012: 103, 109). ²¹ They provide no evidence that the coincidence between the two stemmed from cause and effect. They merely assume this to be the case. The officials who created the U-shaped line, however, did so without considering the Truman Proclamation. The ROC archival files—most importantly those detailing the exact determination of the line—never mentioned the Truman Proclamation, continental shelves, the scope of fishing waters, and scarcely even the United States. Fu as well as Gao and Jia also overlook the logic in the Truman Proclamation and all similar claims by other countries: the claiming of a maritime zone within countries’ continental shelves (Suarez, 2008: 28–29). Most of the waters that the U-shaped line delineated, especially those surrounding the Spratly Islands, extended far past China’s continental shelf. The ROC, furthermore, had not officially declared its support and adherence to the concept of a continental shelf zone when the U-shaped line maps were created. It only advocated a three nautical mile territorial waters zone and a twelve nautical mile contiguous zone (Chiu, 1975: 38). The ROC first officially approved the continental shelf concept nearly a decade after the creation of the U-shaped line, when it helped draft and signed the Geneva Convention in 1958. The ROC government did not ratify it until October 12, 1970 (United Nations, 1964).

Besides the lack of a claim to historic rights waters, nothing indicates that the ROC attempted to enforce such zones throughout the South China Sea. The United States navy by this time reigned supreme in the waters of the South China Sea. ROC naval activity in the region in 1946 and 1947 was largely confined to landing expeditions, supplying garrisons, and protecting a limited fishing zone. The ROC government had more pressing matters to attend to, chief among them the Chinese Civil War. As the tide of the war swung irreversibly in favor of Mao Zedong, and the threat of an invasion in Taiwan loomed in 1949, the South China Sea islands became increasingly trivial to the ROC. By May 1950, the last ROC troops stationed on the islands were recalled to Taiwan (Granados, 2006a: 160, 162). While the ROC sent some troops back to the islands from June to September 1956, only Itu Aba and the Pratas Islands were secured. Naval activity afterward in the South China Sea islands region focused on supplying the garrisons and ensuring that the islands were not infringed upon by others. For instance, on October 1, 1956, a ROC patrol boat and destroyer found Cloma’s brother Filemon’s ship anchored off North Danger Reef. They demanded he leave and promise never to return to the islands. Filemon refused, and discussions dragged into the next day. After issuing a final warning and confiscating his weapons, the two ROC ships released him and his crew and departed. Filemon discovered that their structures on Northeast and Southwest Cay, the reef’s two islands, had been “completely removed” (Hartendorp, 1961: 226–27; Haijun xunyi Nansha haijiang jingguo, 1975: 163–70; Samuels, 1982: 84–85). Developments on the ground during this period confirmed that the ROC’s sole concern was the islands’ land territory, not a massive waters zone.

There is one last consideration. Jacques deLisle notes that the U-shaped line generally ran along the 200-meter isobaths line, a feature usually associated with continental shelves as set out by the Truman Proclamation and the Geneva Convention of 1958. ²² This “implies that China claimed everything beyond the outer limits of rival states’ continental shelves” (deLisle, 2012: 615). While interesting, this logic is flawed. It would mean that the U-shaped line was affected by the Truman Proclamation, for which there is no direct evidence as previously explained. DeLisle also fails to recognize the implication of associating the Truman Proclamation with the line in such a manner. If the ROC had indeed made a historic claim over the waters of the South China Sea in 1946, it willingly diminished what it viewed as a “patriotically sacred” and millennia-old claim for the sake of respecting a year-old principle that was then unprecedented in scope, legally unfounded in international law, and followed by neither the ROC nor any of the Southeast Asian colonies bordering the U-shaped line save the United States in the Philippines. Notwithstanding the inherent contradiction, there simply is no evidence that the ROC government made such a decision.

Enter the PRC

Considering itself to be the sole legitimate representative of China, the PRC adopted the U-shaped line in 1949. Although the line underwent a slight change in 1953—in particular, the removal of the two dashes separating Vietnam and China in the Bay of Tonkin—the same shape remained (Franckx and Benatar, 2012: 91). Like the ROC, the PRC in its early years used the line in a way that supported the islands attribution view. It made no official claim to any waters zone that remotely approached the size of the territory encompassed by the U-shaped line for several decades afterward.

The PRC made its first official claim to the islands in 1951, when Premier Zhou Enlai denounced the joint U.S./U.K. draft for the Treaty of San Francisco: “As a matter of fact, the Paracel Archipelago and Spratly Island, like the entire Nansha [Spratly], Zhongsha [Macclesfield Bank], and Dongsha [Pratas] Archipelagos, have always been Chinese territory” (Zhou, 1990: 41). The PRC simply announced that the South China Sea islands were an inherent part of Chinese territory. It did not mention any special waters zone. Even more telling, its “Declaration on the Territorial Sea” in 1958 announced that:

The breadth of the territorial sea of the People’s Republic of China shall be twelve nautical miles. This provision applies to all territories of the People’s Republic of China, including the Chinese mainland and its coastal islands, as well as Taiwan and its surrounding islands, the Penghu Islands, the Pratas Islands, the Paracel Islands, Macclesfield Bank, the Spratly Islands, and all other islands belonging to China, which are separated from the mainland and its coastal islands by the high seas (隔有公海的). (PRC, 1958)

中华人民共和国的领海宽度为12海里。这项规定适用于中华人民共和国的一切领土，包括中国大陆及其沿海岛屿，和同大陆及其沿海岛屿隔有公海的台湾及其周围各岛、澎湖列岛、东沙群岛、西沙群岛、中沙群岛、南沙群岛以及其他属于中国的岛屿。

This statement explicitly indicated that a belt of high seas separated the Chinese mainland from the South China Sea islands. The PRC did not hold to, nor did it attempt to enforce, a historic rights waters interpretation of the line. Its navy remained largely inactive in the islands region until 1974 (Lo, 1989: 29–29; Samuels, 1982: 67, 87–88).

From that year, however, official PRC claims and protests employed vague terms such as “adjacent” and “relevant” to characterize the waters next to the islands it claimed. The first case was an official PRC statement on January 11, 1974, issued five days before PRC and South Vietnamese forces battled for control of the southern half of the Paracel Islands (the Crescent Group), and in reaction to South Vietnam’s official incorporation of the Spratly Islands on September 6, 1973. It stated that “the Nansha [Spratly], Xisha [Paracel], Zhongsha [Macclesfield Bank], and Dongsha [Pratas] archipelagos are all part of Chinese territory. The People’s Republic of China has indisputable sovereignty over these islands and islets. The resources of these islands and their adjacent seas also belong entirely to China” (Renmin ribao, 1974: 1, italics added). This statement did not clarify the geographic extent or rights of these “adjacent” waters. Thus, it is uncertain whether it can be considered an assertion of a historic rights waters regime.

PRC laws and statements continued this pattern of ambiguity. Article 14 of its EEZ law, implemented on June 26, 1998, stated that “the provisions of this Law shall not affect the historic rights enjoyed by the People’s Republic of China” (PRC, 1998, italics added). This was the first time the PRC government indicated that it possibly held such rights in the region, but it did not clarify what these entailed and where they applied.

On May 7, 2009, China submitted a note verbale to the UN, responding to Vietnam and Malaysia’s joint submission of their claim to an extended continental shelf to the Commission on the Limits of the Continental Shelf. It attached a map of the U-shaped line, the first time the PRC officially presented the line on an international level to illustrate its claim and rebut that of others. However, its only explanation relating to the map was that

China has indisputable sovereignty over the islands in the South China Sea and the adjacent waters, and enjoys sovereign rights and jurisdiction over the relevant waters as well as the seabed and subsoil thereof (see attached map ²³ ). The above position is consistently held by the Chinese Government, and is widely known by the international community.

The continental shelf beyond 200 nautical miles as contained in the Joint Submission by Malaysia and the Socialist Republic of Viet Nam has seriously infringed China’s sovereignty, sovereign rights and jurisdiction in the South China Sea. (PRC, 2009)

While terms such as “adjacent waters,” “sovereign rights,” and “jurisdiction” were used, their scope was not specified. The words “relevant waters” were followed by a reference to the U-shaped line map, without stating whether the “relevant waters” equaled some or all of the waters contained within the line. The confusion was evident in the Filipino note verbale of April 5, 2011, its response to China’s note. The Philippines denounced the U-shaped line as illegal, because its scope and the term “relevant waters” were not clarified, while the line overlapped with Filipino claims in the Spratlys (Government of the Philippines, 2011a). China’s response to the Filipino note on April 14, 2011, did not address these concerns. It simply reiterated that China had “indisputable sovereignty over the islands in the South China Sea and the adjacent waters, and enjoys sovereign rights and jurisdiction over the relevant waters as well as the seabed and subsoil thereof” (PRC, 2011).

This official ambiguity has since persisted. On January 22, 2013, in response to the Philippines’ efforts to bring the South China Sea dispute before international arbitration, the PRC’s ambassador in Manila, Ma Keqing, reiterated Chinese sovereignty “over the islands in the South China Sea and its adjacent waters” (Xinhua News, 2013). On December 12, 2014, PRC foreign ministry spokesman Hong Lei denounced Vietnam for submitting its statement of position to the arbitration panel. He reaffirmed that “China has indisputable sovereignty over the Nansha [Spratly] Islands and their adjacent waters. And it is an indisputable fact that the Xisha [Paracel] Islands are an integral part of China’s territory” (PRC, 2014). Neither Ma nor Hong clarified the scope and rights of these “adjacent waters.”

Conclusion: The Significance of the History of the U-Shaped Line to the Present Dispute

It is because this vagueness continues today that examining the history of the U-shaped line is important. Not only did the PRC adopt the line used by the ROC to represent its claims in the South China Sea, it used this line in the same way until at least 1974, and possibly beyond: as an islands attribution line. There was continuity between the ROC’s and PRC’s interpretation of the line. Therefore, the ROC’s early usage of the line represents the first step to understanding and clarifying how the PRC interprets it today.

This article points toward an important avenue of future research. A thorough comparison between the origins and early usage of the line and the PRC’s position in the South China Sea region since 1974 would reveal changes and continuities on these issues and the reasons for them. Identifying these aspects would help in resolving the disputes over the South China Sea, for instance, by determining how to proceed with negotiations. If the PRC continues to adhere predominantly to the islands attribution view, it would be better first to negotiate less sensitive matters pertaining to maritime areas rather than a delineation of the islands, as this would encounter less opposition from China. Initial limited cooperation among claimants would help to reduce provocations and foster confidence building in the region. Examples could include joint projects in marine conservation, emergency response, anti-piracy, and perhaps scientific exploration and research. Such measures could gradually erode mistrust and increase the chances of success in later rounds of negotiations that address more sensitive topics, such as finally settling ownership over the islands.

Determining how far the PRC still adheres to the ROC’s early usage of the line will help concerned parties understand the PRC’s present claims, and eliminate historical inaccuracies and biases. This would encourage constructive debate and resolution by allowing claimants to sort through worrying aspects of China’s claims that have obstructed progress in the dispute. By the same token, to reveal changes in China’s historical arguments that do not adhere to its original claim, ²⁴ have no foundation in international law, or indicate simple expansionism, will assist non-Chinese claimants to decide which areas of the dispute they must be adamant about.

Of special importance, a balanced investigation of the history of the U-shaped line might lead all claimants to understand that listening to other claims does not automatically mean accepting them. This point is often lost in the wrangling over clashing claims. China’s assertion of “indisputable sovereignty” in the region, for instance, is far too inflexible. It prevents China from realizing that its historical claim raises genuine concerns, and from addressing them. China’s refusal to clarify its historical claims fuels fear among its neighbors, while glaring historical inaccuracies weaken its case and prompt inflexible stances from non-Chinese claimants.

Meanwhile, non-Chinese states’ refusal to meaningfully consider China’s claims, stemming from a lack of understanding of China’s U-shaped line claim, equally discourages peaceful resolution. Thus, the Philippines’ unsuccessful Zone of Peace, Freedom, Friendship and Cooperation plan stated in a footnote that the U-shaped line did not merit consideration, even in areas not disputed by the Philippines (Government of the Philippines, 2011b: 2). ²⁵ This approach prevented China from employing the line even as a basis with which to participate in the proposed resolution plan. The Philippines dismissed China’s views on history and international law so abruptly that China refused even to discuss the plan. Had the Philippines taken China’s claim into consideration, which would not have necessarily meant accepting it, China may have participated and removed ambiguity over the line, thus moving toward resolution. Instead, this incident encouraged China to continue hardline measures in order to “protect” its claims.

Finally, examining the history of the ROC’s usage of the line could help guide the ROC government on deciding what stance to adopt on the dispute. Its claims have been as wide-ranging as the PRC’s, if not more so. On April 13, 1993, under its “South China Sea Policy Guidelines” 南海政策綱領, the ROC officially stated that “the waters within the South China Sea historic waters boundary (歷史性水域界線) are under the jurisdiction of the Republic of China. Our country possesses all rights and interests in these waters” (Executive Yuan of the Republic of China, 1993). The “historic waters boundary” referred to the U-shaped line created in 1948, as the chairman of the Research, Development, and Evaluation Commission of the Executive Yuan clarified shortly afterward (Sun, 1995: 403). The Policy Guidelines did not articulate what “all rights and interests” entailed. A literal reading of “historic waters” would make nearly the entire South China Sea equivalent to the ROC’s internal waters.

The ROC government terminated the Policy Guidelines on December 15, 2005 (Executive Yuan of the Republic of China, 2005). However, its current official position is unclear. Like the PRC, it claims the islands and their “surrounding waters” 周遭水域 (MOFA, 2011). Recent developments have not clarified this ambiguity. On September 2014, ROC president Ma Ying-jeou delivered a speech at the Academia Historica that adhered to the islands attribution view. According to the Economist, he specified that the 1947 claim “was limited to islands and 3 to 12 nautical miles of their adjacent waters. There were, he said, ‘no other so-called claims to sea regions’” (“Joining the Dashes,” 2014). Yet, in a letter to the Economist’s editor on November 1, ROC representative to the UK Liu Chih-Kung stressed that “President Ma did not say that the ROC’s claim was limited to the islands and three to 12 nautical miles of their adjacent waters, since the Location Map of the South China Sea Islands, published by the ROC government in 1947, covers both the islands and their surrounding waters” (Liu, 2014). It is unclear how far these “surrounding waters” extend, but Liu made it clear that it was not limited to twelve nautical miles from the islands. This indicates that the ROC government possibly holds a historic rights or historic waters view. It may also be evidence of confusion or dissension among ROC offficials regarding this stance. There has been no official response to this letter.

The ROC’s actions regarding the South China Sea dispute frequently contradict a historic waters or historic rights waters stance. The ROC has never claimed nor attempted to uphold the right to prohibit or regulate foreign maritime and aerial traffic across the South China Sea, notwithstanding the repealed Policy Guidelines (Wang, 2010: 249). The ROC’s law on the territorial sea and contiguous zone, Exclusive Economic Zone law, and baselines declaration claim only measurable sea zones, using language derived solely from international law. They do not include such terms as “historic rights” and “adjacent” or “relevant” waters (MOI, 1998a; MOI, 1998b; MOI, 1999). The government continues to focus on garrisoning and developing the islands it has retained since 1955, the Pratas and Itu Aba Island. Almost all development there has focused on land territories. For instance, the ROC opened Itu Aba Island to tourism, built an airstrip to bolster the island’s defense in 2007, completed a solar power plant in 2011, and is currently building a port (Lin and Hsiao, 2012: 1–2, 6–7, 13–14; Gold, 2015). The scope of its military patrols is limited to a narrow 10 km (approximately 5.4 nm) belt of exclusionary waters around Itu Aba Island. Given the potentially negative diplomatic consequences of claiming a large historic maritime zone, since archival files support its present focus on the islands, the ROC government might gain from officially declaring an islands attribution stance on the U-shaped line.