Home / Articles / China’s New Pressure on Taiwan in the South China Sea
In October 2020, Hong Kong’s air traffic control denied a Taiwanese flight access to Pratas Island, a Taiwan-occupied feature in the South China Sea. It was the first time that had ever occurred. The refusal, likely prompted by Beijing, might seem to be just another way for China to put pressure on Taiwan, which it has long regarded as a renegade province. But more broadly, the incident reflects a marked change in not only how China sees Taiwan’s remote outposts, but also how confident China is in its ability to control the air and sea spaces of the South China Sea and its willingness to wield that power as a political tool.
The incident began when Taiwan’s air traffic control center notified its counterpart in Hong Kong of the approach of a Taiwanese flight into Pratas Island, as is standard procedure since Hong Kong’s air traffic control oversees the flight information region around the island. But this time, Hong Kong’s air traffic control replied that it “cannot accept this aircraft.” The nominal reason was that the flight could not fly below a certain altitude (which happened to be the ceiling for the aircraft) due to “dangerous activities.” When asked about the nature of the danger, Hong Kong’s air traffic control responded that it “cannot tell you any more about that,” but confessed there was no military exercise nearby or a “notice to airmen” (a warning issued before a military exercise) for the area. Finally, when asked how long the danger would last, it uneasily replied: “eh, now on until further notice.”
Naturally, Taipei has sought to confirm whether Beijing was behind the incident. It is probable that it was. Recent Taiwanese efforts to hinder China’s long-running campaign to undermine Taiwan’s status on the global stage have rankled Beijing. In August and September, Taiwan welcomed two senior officials (including a cabinet-level one) from the United States as well as the head of the Czech Republic’s Senate. At the same time, Taiwan’s foreign minister caused a stir by calling on the international community to form a coalition to resist Chinese aggression. Perhaps the most galling to Chinese leaders was Taiwan’s support for Hong Kong’s protesters as they demonstrated against their city’s Beijing-backed government. And when some of the protesters sought to flee, Taiwan offered those who evaded capture refuge.
Historically, Beijing has often expressed its displeasure with Taiwan through some form of intimidation. During the 1990s, China fired a series of ballistic missiles into the Taiwan Strait. Since May 2020, it has conducted several big military exercises near the Pratas Islands (of which Pratas Island is the only one above sea level). But it had never before attempted to deny Taiwan access to the islands themselves. Even Taiwan’s main opposition party leader, Johnny Chiang, wondered aloud, “Does this mean that the Communist’s military has already begun joint blockade war operations in addition to regular exercises and intrusions?”
Though often overlooked, Taiwan maintains two small outposts in the South China Sea. The first is Pratas Island, whose strategic importance belies its tiny size. Some 310 km off Hong Kong and 430 km south of Taiwan’s southernmost port of Kaohsiung, the island is ideally situated to give Taiwan early warning of any attack that China might mount against it from the south. Meanwhile, the island’s 1,500-meter long runway provides Taiwan with a good base from which to conduct anti-submarine warfare missions in the event Chinese submarines try to blockade Kaohsiung. And, of course, Pratas Island is the only link between Taiwan and its other South China Sea outpost, Itu Aba (or Taiping in Taiwan), some 1,175 km to the south of Pratas. Hence, it is no surprise that Taiwan quickly set about fortifying Pratas Island soon after the United States handed it over to the Republic of China (i.e., Taiwan) following World War II. About 500 Taiwanese marines still guard the island from its network of underground bunkers.
Itu Aba is the only outpost that Taiwan holds in the disputed Spratly Islands. Like Pratas Island, Itu Aba has long been occupied by Taiwanese forces. In 1999, Taiwan replaced its marine garrison with a 130-man coast guard unit, albeit one armed with eight 40-mm anti-aircraft guns, 120-mm mortars, and AT4 light anti-tank missiles. Over the following decade, Taiwan steadily improved the island’s infrastructure. By 2008, it had completed a 1,200-meter runway that could accommodate military aircraft. Then, in 2015, Taiwan expanded the airfield’s apron and taxiways and built a $108-million port capable of handling its deep-draft naval vessels. All the construction has not only allowed Itu Aba to provide Taiwanese fisherman a safe harbor in a storm, but also made it far easier to supply and defend. Indeed, within a year after the runway was finished, Taiwan dispatched its P-3C anti-submarine warfare aircraft to the island for the first time.
Despite keeping a generally low profile in the hotly contested South China Sea, Taiwan’s presence in the region has not gone without incident. In 2013, the Philippine coast guard opened fire on a Taiwanese fishing boat, killing one of its crew, near Pratas Island. Taiwan responded by organizing a large show of force that included a Kidd-class destroyer, two Lafayette-class frigates, three coast guard vessels, and two Mirage 2000 fighter jets. The following year, it mounted an even bigger show of force near Itu Aba with several frigates and amphibious ships, including a Newport-class landing ship tank, which disgorged Taiwanese marines and 20 amphibious assault vehicles onto the island. It was the largest amphibious exercise that Taiwan held in the Spratly Islands since the 1990s.
Quiet on the Far-Off Front
Yet, for all of Taiwan’s construction and military exercises, China never raised a word of protest. Nor did China do so when Taiwan’s then-President Chen Shui-bian visited Pratas Island in 2005 or Itu Aba in 2008. And, despite the ratcheting up of tensions in the South China Sea during the 2010s, not a peep was heard from China over official visits to Itu Aba by Taiwan’s then-defense minister in 2014 or Taiwan’s then-President Ma Ying-jeou in 2016. As one commentator noted, “Taipei knows it is the only claimant that (China) will not bother.”
Given the often-fraught relations between China and Taiwan, such silence seems unusual. But, as it happens, the dashed-line map upon which Beijing’s South China Sea claims rest was actually created by the Republic of China, which now governs from Taipei. So, when the Philippines challenged Beijing’s claims on the basis of the United Nations’ Convention for the Law of the Sea (UNCLOS) before the Permanent Court of Arbitration (PCA), it was Taiwan that came to China’s aid. In March 2016, as the court deliberated, Taiwan issued a white paper that echoed China’s “historic rights” argument that “The Spratly Islands, Paracel Islands, Macclesfield Bank, and the Pratas Islands were first discovered, named, and used by the ancient Chinese, and incorporated into national territory and administered by imperial Chinese governments.” And when the PCA ultimately ruled against China (and, presumably, Taiwan), both refused to “recognize or accept” the ruling. Though many issues divide Beijing and Taipei (not the least of which is Taiwan’s subordination to Chinese rule), sovereignty over the islands in the South China Sea is not among them.
Their closeness on the matter was underscored in 2015, as Taiwan was planning the construction of its new port on Itu Aba. Unable to find a local shipper capable of transporting the necessary building materials to the island, Taipei turned to Shanghai Zhenhua Heavy Industry, a Chinese state-owned engineering company, to do the job. And so, the world was treated to the odd sight of a Taiwanese patrol boat escorting a Chinese heavy-lift vessel to a strategic Taiwan-held island in the South China Sea.
Evidently, China has seen little profit in clashing with Taiwan over the islands it occupies in the South China Sea. In fact, Taiwan’s actions have raised more vocal opposition in Hanoi and Manila than in Beijing. China may have ultimately believed that since it will one day bring Taiwan and its territories under its control any Taiwanese effort in the meantime to improve the islands would be an eventual benefit to China. The only major difference between China and Taiwan in the South China Sea seemed to be over a possible Chinese air defense identification zone (ADIZ) over its waters, similar to the one that Beijing set up over the East China Sea. In 2016, Taiwan noted that it would not recognize such an ADIZ over the South China Sea.
Change of Course
China’s likely recent refusal to grant Taiwan air access to Pratas Island was a clear departure from the way Beijing has long treated Taiwan’s South China Sea outposts. Practically, that matters because China is now in a much better position to enforce its refusal. At one time, Taiwan’s air and naval forces were more than a match for China’s and could reliably keep the lines of communication between Taiwan and its outposts open. That is no longer true. China’s military modernization and expansion over the last quarter century has essentially closed the capability gap across the Taiwan Strait. Hence, Taipei is rightly nervous about what might happen next, whether China extends its access denial to sea traffic or to Itu Aba.
But in a larger sense, what China’s denial of air access has demonstrated is China’s growing comfort with its own power. Its efforts to control the waters of the South China Sea and the airspace above it, in this case, have become more open. And it has become confident enough to break with its own long-established norms that have kept the peace in pursuit of its contemporary political interests. Such confidence suggests that Chinese leaders are far from being ready to temper their strident assertiveness. That should worry many governments, not just the one in Taipei.
The views expressed in this article are those of the authors alone and do not necessarily reflect the position of the Foreign Policy Research Institute, a non-partisan organization that seeks to publish well-argued, policy-oriented articles on American foreign policy and national security priorities.
 Republic of China (Taiwan) Foreign Ministry, Position Paper on ROC South China Sea Policy, Mar. 21, 2016, p. 1.
 Taiwan has the better rationale for its refusal. Taiwan is neither a member of the United Nations nor a signatory to the United Nations’ Convention for the Law of the Sea.