During the second decade of the twenty-first century, the South China Sea (SCS) has emerged as a focal point for confrontation between China and the United States [49] and largely contributed to the difficulties in China–US relations. The intensity and seriousness of China–US competition in the SCS have been reported, but the causes and content remain unclear. In both countries, the prevailing view is that the other side is the root of the problem. China is accused of coercing US allies and partners, militarizing disputed features, and attempting regional hegemony, and the United States is accused of “playing the South China Sea card” and attempting to contain China’s maritime rising. Objectively, the perceptions of both sides are biased and do not explain the many incidents and complicated situations in the SCS since 2009. Notably, China had not considered the United States as its main opponent in the SCS until at least 2014 and had merely attempted to prevent US involvement in disputed issues. Thus, at the beginning of 2015, China showed a lack of preparation for the sharp US response to its island-building activities.Footnote 1 China has been known as increasingly assertive in its capacity building and safeguarding maritime rights with its maritime rising. However, based on its less coordinated and organized policies and actions, it has neither a clear strategy nor a detailed plan to control the SCS. The United States does not want China’s presence in the SCS to increase, but US policy toward China in this regard is mixed with legal and political concerns. Containment continues to be US policy; however, this tendency does not explain the Obama administration’s trying to have a balanced policy toward this issue at least until 2013. Both sides have overstated each other’s capacity and intentions in the SCS and neither side planned to enter such a severe stalemate. Obviously, these individual actor’s interpretations are not convincing, and other systematic explanations are necessary.

From the perspective of China–US interactions on the SCS, there are mainly three types of explanations for the causes of China–US competition, of which, power competition is the most highlighted. The US Government has long believed that Beijing wants to push the United States out of Asia. Indeed, the shifting power dynamic in the region, with its attendant changes and uncertainties, has taken on a new level of complexity because of the strain on US–China relations writ large [40]. From the realist perspective, it is reasonable to propose that a changing balance of power is the main driver, but this is oversimplified without considering the complex situation of the SCS. At least from 2009 to 2012, power competition was not the main focus of China and the United States on the SCS issue.

Disputes over maritime rule and order are another mainstream explanation for the China-US competition especially in western academia. Some even declares that the key dynamic is a “battle of legal regimes,” somehow a political contest of wills that manifests in a duel between two competing systems of authority—the US-underwritten system of the free sea versus the Chinese vision of a closed, China-centric, and unfree sea [50]. Undoubtedly, there are many serious differences in the maritime rules and the interpretation of some articles of the United Nations Convention on the Law of the Sea (UNCLOS) and other international law between China and the United States. Considering that these types of differences have existed since 1990s, why has the controversy become so intense in the recent decade?

Third-party factors have surged in the last decade, and China–US relations are increasingly affected by other actors, including the Democratic People’s Republic of Korea (DPRK), the Republic of Korea (ROK), Japan, Vietnam, the Philippines, and Russia [28, 57]. Regarding the SCS, third-party factors are also an important variable in China–US frictions. Between 2009 and 2012, most of the diplomatic friction and confrontations between China and the United States over the SCS were, to a certain degree, responses of China and the United States to the actions of the Philippines and Vietnam, for political reasons such as domestic legitimacy and international reputation.

Obviously, all the aforementioned explanations on the China–US conflict and competition over the SCS have some explanatory power and limitations. None of the explanations is comprehensive, and one theory cannot answer all questions. Moreover, what works in one period does not always work the same manner in another period. At different times, the focus of the China–US struggle is different, and little research has been conducted on this topic.

Thus, this article attempts to conduct a comprehensive analysis of the three major factors, to clarify the main mechanisms they play in China–US competition in the SCS and assess the relations among different factors, and then verifies these hypotheses in different periods. Moreover, this study also aims explore some basic trends in the long-term China–US competition over the SCS.

To achieve that objective, I review the position documents, official statements, and operations of both sides in detail on the SCS, review the main reactions and interactions between China and the United States in major incidents according to open reports and research, and analyze the development trajectory of their strategies and policies related to the SCS through deductive reasoning. Additionally, I share my conclusions based on my observations of the China–US competition since 2009 and on interviews with more than 20 Chinese officials involved in incidents and policies of the SCS from China’s Foreign Ministry, Chinese Navy, and China’s Coast Guard, which, to some extent, help overcome the limitation of the lack of information on China’s decision making.

It should be mentioned that this article may nevertheless be perceived as having a Chinese perspective. However, this possible limitation can to some degree be an asset for improving international academics’ understanding of China’s position on the SCS.

Three Major Variables for China–US Competition in the SCS

Most of the disputes and conflicts are related to three variables of—power competition, disputes over maritime rules, and third-party factors—which have been and will exist for a long time, despite the changes in governments in both countries.

Power Competition

Although the military force of China has long been insufficient to challenge that of the United Sates at the global level, in the local sea areas of the Asia-Pacific, a more balanced power distribution is replacing the unipolar structure dominated by the United States. A substantial power transition between China and the United States, as mentioned by the strategic community, has occurred in the Asia-Pacific, especially in East Asia. According to even the most cautious and conservative opinions, China’s maritime rise will lead to limited but substantial changes in the power structure. “While the USN has dominated Asian waters in general for the past half-century, China is now challenging that dominance” [9].

Most conspicuously, the United States is unwilling to adapt to this power transition, despite recognizing the changing balance of power, and is refusing to share the power. “Today’s security environment is dramatically different than the one we’ve been engaged in for the last 25 years and it requires new ways of thinking and new ways of acting” [5]. China has become a major maritime power and a strategic competitor, primarily in the Asia-Pacific, which has begun to be acknowledged by the United States in approximately 2009 and been an evolving process [49].

There are several US goals for strategic competition with China in the SCS (SCS), but fundamentally and generally, “maintaining a regional balance of power favorable to the United States is the core” [10]. Even China does not have the intention to challenge the United States, China’s actions of capacity building and maritime rights safeguarding would be seen by the United States as a serious challenge to its maritime hegemony [24]. In the US perspective, China’s rising power itself is the largest way of changing the status quo. “Even if Chinese control began peacefully, there would be no guarantee that it would stay peaceful.” To continue to avoid conflict between the two nations over the SCS, the United States should maintain its policy that has been successful for over 100 years: prevent any other power from commanding it [45]. Except for the sovereignty of Nanhai Zhudao and maritime rights, China has not released details on its strategy toward the SCS [37], but clearly, China plans to strengthen its power presence and maritime rights safeguarding and improve its regional influence. Thus, competition between the two parties for power is unavoidable and will continue to increase.

Disputes over Maritime Rules

China and the United States have ideological differences on the SCS that should be considered when reflecting on how to interpret the specific provisions of international law including the UNCLOS. Additionally, there are some different maritime practices in China’s neighboring seas, especially in the SCS. Due to the difference in history, geography, and political culture, China pays more attention to sovereignty and security, while the United States pays more attention to freedom of access. However, these types of differences have been exaggerated for strategic and political reasons. Some individuals even posit that the China–US confrontation in the SCS represents the game between the continental and maritime systems [14]. These differences are serious but not as large as what most observers think.

Prior Consent for Innocent Passage

Both China and the United States agree with the principle of innocent passage in territorial waters. Differences remain over whether a coastal state can require prior permission or notification before a foreign warship conducts innocent passage in its territorial seas. China insists that coastal states have the authority to require prior permission and does so according to its domestic law, and the United States insists that coastal states have no international legal basis for doing this. China and the United States represent merely two types of practices of innocent passage. Approximately 30 coastal states worldwide, including China, require permission or notification by foreign warships prior to exercising the right of innocent passage through its territorial sea.

Excessive Maritime Claims

The United States insists, “China’s maritime claims in the SCS, exemplified by the preposterous nine-dash line, are unfounded, unlawful, and unreasonable, and are without legal, historic, or geographic merit” [62]. Chinese officials do not discuss the dash line too much, and the term “dash line” is rarely used in government statements. According to the government statement issued on July 12, 2016, three of four categories of claims as sovereignty over Nanhai Zhudao—internal waters, the territorial sea and contiguous zone, and the exclusive economic zone(EEZ) and continental shelf [37]—are based on general international law and UNCLOS, not the dash line. Regarding the fourth claim of historic rights related to the dash line, China may have two arguments. One argument is that because UNCLOS has not specified what constitutes historic rights, there exists a degree of ambiguity in China’s “dash line” claims. Moreover, even the historic rights of the dash line could not be included in UNCLOS, which is not unusual because in the Preamble, UNCLOS affirms “that matters not regulated by this Convention continue to be governed by the rules and principles of general international law” [58].

Fundamental differences also emerge over the circumstances in which international law permits the drawing of archipelagic baselines and straight baselines. China published archipelagic baselines for the Paracel Islands in 1996 and is expected to do so again for the Spratly Islands. The United States posits that Articles 46 and 47 of UNCLOS only permit the drawing of archipelagic baselines by archipelagic states. China argues that UNCLOS does not exclude the possibility that non-archipelagic states can draw archipelagic baselines and posits that because UNCLOS does not define what a valid archipelagic claim by continental states is, such claims would be defined by state practice and governed by customary international law.

The United States posits that, according to the SCS Arbitration Award 2016, low tide elevations such as Mischief Reef and Subi Reef do not generate maritime entitlements, and high tide elevations such as Fiery Cross Reef and Cuarteron Reef are rocks with only 12 nautical miles of territorial sea. While, China does not recognize the Arbitration and its Award, always upholds the Spratly Islands as a unit to claim its maritime rights, and does not accept the legal nature of these features being determined one by one [33].

Military Activities in the EEZ

Controversy exists worldwide on how to guarantee the freedom of military action of other countries in EEZ under the circumstances of ensuring the security of coastal States. In China’s perspective, Article 59 of UNCLOS allows for subjectivity and interpretation of what due regard for coastal states’ rights and duties means, and that under its interpretation, user states should give due regard to not only to economic concerns but also to the security concerns of coastal states. Although the US position is that the EEZ provides coastal states the right to regulate economic activities (e.g., fishing and oil exploration) within their EEZs, it does not give coastal states the right to regulate foreign military activities in the parts of their EEZs beyond their 12-nautical-mile territorial waters [11]. In the EEZ, there are varying views—from some restrictions to no restrictions. China’s position is just between the most conservative and the most radical. China stipulates restrictions on marine science surveys in the Law of the People’s Republic of China on the Exclusive Economic Zone and the Continental Shelf enacted in 1998 [56], but no regulations on foreign military activities are provided.

In reality, the US warships and military aircraft have complete freedom in the Chinese EEZ beyond 12 miles of its territorial baselines and controlled islands and reefs in Spratly islands, although China does not welcome and often monitors the operations in accordance with international practice. China’s opposition to US close-reconnaissance and other aggressive activities in its EEZ is more because of security concerns than legal reasons. In China’s debate, the United States may have the right to perform these actions, but they need to decrease the frequency and intensity in consideration of China’s security.

Notably, China’s views of and practices in the EEZ have been increasingly open when its military forces accelerate their overseas activities. The perception gap between the two sides on this topic has not disappeared but is gradually narrowing. Future legal differences will center on specific operations such as marine scientific research (MSR), whether these operations are military or scientific, and whether resource and environmental protection should be considered in military operations.

Settling Maritime Disputes

The United States always reiterates that “force or coercion should not be used as a means of settling disputes between countries, and certainly not as a routine or first-resort method” [11], emphasizing the importance of third-party mechanisms (e.g., the mandatory arbitration of UNCLOS) and demanding that China abide by the Arbitration Award. China adheres to the position of settling disputes through negotiation and consultation and managing differences with concerned parties through relevant rules and mechanisms; however, on the issues of territorial sovereignty and maritime delimitation, China wants to reserve the right to self-defense in the worst scenario. China accepts neither any recourse to third-party dispute settlements without the consent of the parties concerned nor any solution imposed on it [36].

Third-Party Factors

In the SCS, the meaning of third-party factors differs between China and the United States, respectively, domestic legitimacy and international reputation. For China, the political significance of the sovereignty over islands and reefs cannot be neglected. In the context of highly developed and diversified public opinion and increasingly close domestic and international political ties, sovereignty has been endowed as a symbol of national rejuvenation and the rise of the nation and directly related to the ruling status of the Communist Party of China and the political security and stability of the country. Undoubtedly, Chinese maritime nationalism is expanding with the China’s increasing power [46]. Thus, as to the violations of China’s sovereignty and maritime rights by some neighboring countries, the Chinese government has been facing increasing pressure and criticism at home [21]. Defending sovereignty over the islands and reefs does not mean China will consider reclaiming the occupied islands and reefs as a realistic goal or resorting to military means. However, China must stick to the bottom line on legal principles, and diplomatically insist on its claims, and could not accept new losses, either on the spot or legal.

The United States has established a widespread security network around the SCS and maintains an alliance with the Philippines and close partnerships with almost all the Association of Southeast Asian Nations (ASEAN) member states. Since 2009,the United States has been making an increasing number of security commitments to its allies and partners with respect to the SCS and other maritime disputes involving China. Not surprisingly, China’s actions for safeguarding sovereignty and maritime rights would be opposed and fiercely responded to by the foresaid third parties. As their close ally and sometimes partner, the United States should respond to China’s actions by meeting the expectations and demands of these third parties while showing its dominance. The United States even posits that China may be attempting to use disputes in the SCS to drive a wedge between the United States and its regional allies and partners, to weaken the US-led regional security architecture and facilitate greater Chinese influence over the region [10].

The United States may want to maintain its neutrality on the disputed issues, but in reality, this position is difficult for the aforementioned reasons. Additionally, the US message seems “as if it is opposed to any Chinese activities that involve an increase in presence or capability in the area, with little serious reference to the provocative actions of any other claimants, in particular Vietnam and the Philippines” [53]. While, China’s actions and reactions toward third parties for safeguarding its sovereignty and maritime rights would be considered by the United States as coercing neighbors and undermining regional order. In this manner, disputes and conflicts between China and the third parties will lead to friction between China and the United States. From 2009 to 2012, “US-China relations are generally shaken not by intrinsic differences between Washington and Beijing, but by disagreements involving third parties” [57].

The United States has also increasingly considered these third parties as part of its rivalry with China and requested that they choose sides. From a broader perspective, “the struggle over the South China Sea is not about ‘rocks,’ but about whether states in Southeast Asia and the greater Indo-Pacific region will align with the United States or China” [1].

Different Influence of these Variables in Different Periods since 2009

More than a decade of experience has shown that major incidents often highlight one of these variables, changing the pattern of competition and the bilateral interaction direction in the SCS. Therefore, I use major incidents, which can change the sequence of roles of different variables, to divide the time periods. China’s Note to the United Nations with dash line map and other disturbances in 2009, the SCS Arbitration in 2013, and the emphasis on strategic competition with China in the United States in 2017 provide the main basis for division. Thus, this study examines three periods: 2009–2012, 2013–2016, and 2017 to 2020.

From 2009 to 2012

In this period, third party factors have the strongest explanatory power. China’s maritime rise, the US Pivot and Rebalance to Asia, and the pressure of domestic system building made the Philippines and Vietnam and other claimants take a series of radical actions in the SCS. In response to these aggressive moves, China’s reactions and America concerns intertwined, leading to the growing conflicts between both sides on the SCS issue. Power competition began to come into sight and differences over maritime rules loomed large, which also complicated the Sino-US interaction in the SCS.

Undoubtedly, 2009 was a watershed in the development of the SCS situation. From 2009 onwards, a series of intertwining factors caused countries such as Vietnam and the Philippines to take the lead in disrupting the relatively calm status quo. First, China’s ever-growing strength elicited Vietnamese and Philippine strategic anxiety; positing that “there is no time like the present,” they attempted to achieve more fait accompli and resources before China’s strength further increased. Next, the worldwide practices of the EEZ and continental shelf systems inspired Vietnam, the Philippines, and other countries’ claimants to accelerate their offensive. Finally, the US “Pivot to Asia” and promotion of the “Asia Pacific Rebalancing” strategy enthused and roused some countries, such as Vietnam and the Philippines, which hoped to take advantage of the US “Pivot” to provoke China.

Under these circumstances, other claimants such as the Philippines and Vietnam took a series of proactive actions on the disputed issues, bolstering the administrative jurisdiction of disputed islands and reefs and strengthening maritime law enforcement. From 2009 to 2012, actions taken by other claimants for controlling disputed land features and energy exploration in contested waters prompted a rapid increase in the average number of incidents, from 15 to more than 20 times every year [67]. Two typical cases are the submission of Limits of the outer Continental Shelf in 2009 and the Scarborough Shoal incident in 2012.

These intensive actions aroused great concerns in China. With rapid development of mass media, the public’s awareness of and voice for the protection of maritime rights had increased sharply, and sovereignty and maritime rights had become sensitive topics in Chinese politics. In 2010, largely out of concern for the situation in the SCS, China’s defense white paper stated that pressure on China to defend its maritime rights had increased [38]. Beijing occasionally implemented direct actions against other claimants; however, in most cases, these activities “have taken place in response to what China views as growing and more assertive challenges to its claim occurring since roughly 2007, challenges that require a response in turn” [20]. Moreover, China’s greater presence and activism were to some extent a logical consequence of its increasing capabilities [52]. The actions of the Philippines and Vietnam and other ASEAN claimants doubled with reactions of China and led to friction and a series of confrontations. The Scarborough Shoal incident was considered by Beijing as the “last straw on the camel’s back” for its restraint policy. In April 2012, photos of the arrested Chinese fishermen being stripped to the waist and exposed to the harmful rays of the sun on the deck made headlines in print and digital media in China [21], triggering an outcry among the Chinese public, forcing Beijing to implement serious countermeasures.

All these events occurred while the United States was pivoting to Asia. Shortly after taking office in January 2009, President Barak Obama signaled that the United States would correct the Bush administration’s misplaced foreign policy by shifting its strategic priority to the Asia-Pacific region; notably, the SCS issue was the focus of that pivot. In that period, Vietnam and the Philippines were accelerating the internationalization of the SCS issue, with high expectations on the United States. In the 2012 Scarborough Shoal crisis, Manila stated that it would seek “maximize” US involvement [17]. How the United States manages the SCS issue would test the determination and connotation of its pivoting to Asia. Kurt M. Campbell, the Assistant Secretary of State for East Asian and Pacific Affairs from 2009 to 2013 said: “When allies are facing down Chinese territorial provocations, and when the South China Sea risks becoming a so-called ‘Chinese lake,’ policy initiatives should lean more toward signals of resolve that make clear American commitment to sustaining peace and stability” [4]. The US pivot had, to a certain degree, contributed to the confidence of the other claimants to challenge China.

Also in 2009, a series of close, intense interactions between the United States, the Philippines, and Vietnam triggered China’s suspicions of US intentions to Chinese sovereignty and security. In early 2009, when disputes arose between China and the Philippines over the latter’s adoption of the Territory Baselines Law, President Obama called President Gloria Macapagal-Arroyo to reaffirm their mutual security relationship and the US commitment to the Visiting Forces Agreement. The timing of the call was widely viewed as a gesture of support for the Philippines in its altercation with Beijing [51]. On multiple occasions from 2008 to 2009, the United States demanded that Beijing stop intimidating US companies undertaking commercial activities in Vietnam’s oil and gas sector in the SCS. As tensions mounted between China and Vietnam, Vietnam became more receptive to increasing its defense relations with the United States [55].

Power competition was another important factor. Whether pivoting to Asia or rebalancing to the Asia-Pacific, checking and balancing the increasing power of China was the main objective. Naturally, the SCS issue had gradually become a major tool for the United States to advance its Asia-Pacific strategy. By mid-2010, the United States had concluded that Beijing’s increasing assertiveness in the SCS and elsewhere required a firmer US response. China interpreted the Obama administration’s firmer response as a U-turn in policy and reacted angrily [49]. To pivot and rebalance to Asia, the United States was more interested in becoming involved in the hot-spot issues and devoted more resources to dealing with the SCS disputes, encouraging some ASEAN claimants to implement more drastic measures. At that time, the United States was not the originator of these crises and frictions, although the saying that “the United States is the boss behind the scenes” had become well known in China. The United States did want to use the SCS issue to serve its strategy but was worried that the situation was out of control and wanted to be an “honest broker.” In reference to the Scarborough Shoal incident, the then Secretary of State Hillary Clinton reaffirmed the 1951 treaty in May 2012. However, US officials declined to discuss publicly how the treaty would apply to Philippine claims in the SCS [61].

US diplomacy aimed at supporting ASEAN and its member states while avoiding escalation with China. However, the US diplomatic–economic–military rebalance, the strengthening of allies and partners, and the ongoing dispersal of forces had created a parallel impression that containment was the strategy [3]. Diplomatic and linguistic conflicts emerged. At the July 2010 annual meeting of the ASEAN Regional Forum, Hillary Clinton delivered a public statement on the US positions on the SCS, in which she emphasized “freedom of navigation,” “non-use or threat of force,” and “compliance with international law” [7] and did not mention “China.” Nevertheless, several elements of her statements were directed against China more than any other claimant [19]. Hillary Clinton later admitted, “That was a carefully chosen phrase, answering the earlier Chinese assertion that its expansive territorial claims in the area constituted a ‘core interest’” [8]. In response, China’s Foreign Minister at the time, Yang Jiechi, gave a speech in which he asked seven rhetorical questions directed at the United States [16]. The two officials met privately, and a heated dispute between them over the SCS has been reported. This diplomatic confrontation marks that the SCS, strategically significant for the first time, has been a major issue between China and the United States.

Bilateral differences over maritime rules were triggered by the USNS Impeccable incident and China’s submission of its claims with the dash line map. While these conflicts represented two distinct disputes in maritime Asia, they both prompted the United States to notice a “growing assertiveness by China in regard to what it sees as its maritime right” [39]. For China, US reactions and accusations were old tune, but much tougher, forcing China to pay more attention to US factors in the SCS.

The Impeccable incident in March 2009 was worldwide news. Reports said that from March 5 to 8, several Chinese vessels operated abnormally close to the Impeccable as it was engaged in undersea intelligence collection in China’s EEZ just 75 miles south of Hainan [22]. On March 9, Department of Defense Spokesperson Bryan Whitman issued an official US statement on the incident, stating that China “violated the requirement under international law to operate with due regard for the rights and safety of other lawful users of the ocean” and that “China and other coastal states ‘do not have the right under international law to regulate foreign military activities’ in their exclusive economic zones” [18]. Subsequently, the then Commander of US Pacific Command, Admiral Timothy Keating, called the Impeccable standoff a “troubling indicator that China, particularly in the South China Sea, is behaving in an aggressive, troublesome manner and [is] not willing to abide by acceptable standards of behavior or ‘rules of the road’” [32]. At a regular press conference on March 10, Foreign Ministry Spokesperson Ma Zhaoxu claimed that the US charges were “flatly inaccurate and unacceptable to China” and that Impeccable’s presence in China’s claimed EEZ had been in violation of Chinese domestic law and international law [30]. According to this type of official statement, China was not against all foreign military activities in its EEZ, but some, such as the Impeccable operation, were thought to have damaged the environment and violated China’s regulations on MSR, although the United States argued it was military activity. Moreover, some informal statements from some of China’s senior officials on this incident [22] created confusion over China’s claims and increased US concerns and doubts on China’s interpretation of international law and growing maritime assertiveness [31].

Following the United Nations’ submission of a dash line map, which for China was merely a response and countermeasure to the joint submission by Malaysia and Vietnam, the United States expressed concerns about “claims to ‘territorial waters’ or any maritime zone that does not derive from a land territory” [26]. In Hanoi, in 2010, Secretary Clinton explained the principles governing US policy in the SCS and said, “claims to water could only be based on legitimate land-based claims” [8]. Although the United States had shown restraint in its direct criticism of China, China regarded it as a sign of increased US involvement in the SCS.

From 2013 to 2016

Legal differences became the most important reason for the deterioration of China–US interaction in the SCS from 2013 to 2016. Different interpretations on juridical status of features and the dash line and positions on the SCS Arbitration substantially affected the mutual trust. Power politics was deepening, and the influence of third-party factors had a new expression.

On January 22, 2013, the Philippines initiated the SCS Arbitration procedure. On July 12, 2016, and unexpected by China, the arbitral tribunal issued the Award of this case and made a series of bold and absurd declarations [43]. Although there was no direct evidence that the United States had been involved in the arbitration procedure, it did legally challenge China’s actions. The most noteworthy example was that the United States had started to openly support the Philippines, as US Assistant Secretary of State Daniel Russel demanded that China clarify the “so-called nine-dash line” [48]. Subsequently, more US senior officers accused China of violating UNCLOS. On December 5, 2014, the US State Department released a report called China’s Maritime Claims in the SCS, analyzing China’s maritime claims in the SCS and outlining the legal challenges to these possible claims [41]. In response to legal challenges by the Philippines and the United States, on December 7, 2014, China’s Ministry of Foreign Affairs issued the Position Paper [33], incisively identifying inconsistencies and contradictions in the Philippines’ arbitration case, by presenting evidence and a logical explanation.

After the arbitrational ruling, the United States took the lead in supporting it and requesting that China accept it, stating that “the Tribunal’s decision is final and legally binding on both China and the Philippines” and expressing “its hope and expectation that both parties will comply with their obligations” [26]. China has made some progress on clarification, especially in the Statement of the Government of the People’s Republic of China on China’s Territorial Sovereignty and Maritime Rights and Interests in the South China Sea [37]. However, China opposes mandatory arbitration and third-party involvement and prefers direct negotiation between disputing parties, which is related to Chinese tradition and experience rather than China’s attitude toward UNCLOS.

The arbitration process has inadvertently deepened the strategic rivalry between the United States and China, and the overt efforts by the United States and other powers to force Beijing to accept the ruling would almost certainly substantially damage China–US relations [54]. The Foreign Ministry Spokesperson, on July 13, 2016, stated that in characterizing a US State Department statement calling for Beijing and Manila to comply with the legally binding ruling of the arbitral tribunal, the United States “turned a blind eye to the facts” and thereby went against the spirit of the rule of law, international law, basic norms governing international relations, and its declaration of not taking sides on issues concerning territorial disputes. The United States continued to urging others to abide by UNCLOS while refusing to ratify the Convention to this day [35]. According to my interviews with some officers and review of the literature, the view that “the US-led Western powers manipulated the process” [68] is considered very convincing in China. While, for the US, China’s “four noes” toward the Arbitration and its Award is a direct manifestation of non-compliance with international law.

In this period, the arbitration gained wide attention and participation from the academic community and the public in both China and the United States, making the SCS a political issue. Both parties had little room for policy maneuvers and had to defend their policies domestically and internationally, intensifying the contradictions and differences.

As to the competition over power, China’s massive reclamation work in the disputed Spratly Islands between 2013 and 2015 was a turning point in US policy toward the SCS [39]. This pivot occurred mainly because Chinese bases in the SCS could complicate the ability of the United States to intervene militarily in a crisis and conduct other military operations [10]. Chinese reclamation had not gotten serious reactions from the United States in the beginning, but the Obama administration, in early 2015, became much more pronounced [2] when the island construction became “too quick and too much” [15].

Strategic observers from both China and the United States agree that Chinese land reclamation and the US reactions have highlighted the China–US strategic competition in the SCS. For China, the aim of this reclamation was mainly to remedy historic gaps with other claimants in infrastructure investment and to bolster the power presence in the Spratly Islands.

However, the United States disagreed with the changing balance of power and exaggerated the military potential of these outposts: On May 14, 2015, the then Assistant Secretary of Defense said, “China’s actions could pose a range of military implications, such as developing long-range radars and intelligence, surveillance and reconnaissance aircraft to berthing deeper draft ships and developing a diversion airfield for carrier-based aircraft” [13]. In the Asia-Pacific Maritime Security Strategy, the Pentagon stressed that “Chinese latest land reclamation and construction will also allow it to berth deeper draft ships at outposts; expand its law enforcement and naval presence farther south into the South China Sea; and potentially operate aircraft – possibly as a divert airstrip for carrier-based aircraft” [59].

From May 2015, militarization had become an important issue for the United States. The Obama administration repeatedly expressed concerns about the militarization of the SCS and demanded that China refrain from doing so. After the meeting between President Obama and President Xi Jinping at the White House in September 2015, the United States deemed that President Xi had made a “Non-Militarization Pledge” in the SCS. However, this type of US judgment is unsubstantiated. Prof. Taylor Fravel said that “what Xi meant by his statement depends on how he or China defines the term ‘militarization’” [42]. A clear, not overly broad definition of militarization is necessary to assess China’s actions. In the Chinese language, militarization or non-militarization is a degree rather than a result, which would be misunderstood when translated into English. In fact, President Xi’s statement is consistent with China’s policy on the deployments of the islands and reefs, that is, how much defense China will deploy on the Spratly Islands depends on the threat that China perceives [34]. The statement did demonstrate goodwill and the intention of restraint, but these aspects have not been studied well, and the United States just follows its logic to demand that no weapons can be deployed. Additionally, China criticizes the United States for having a double standard on militarization and ignoring other disputants’ military deployments on disputed islands and reefs and its own intense military activities around these features [66].

As a direct military response to China’s island construction, the United States launched a new type of freedom of navigation operations (FONOPs) against Chinese-held islands and reefs. The US Navy is undertaking FONOPs worldwide; however, the USS Lassen operation on October 27, 2015, had implemented a new style in which professional military operations had become even more politicized and publicized. From China’s perspective, this type of FONOP is a pure game of power politics.

Third-party factors also had new developments. As aforementioned, the United States was siding more with other claimants on maritime delimitation and legal issues such as the arbitration; in response, China became suspicious and exaggerated the intentions of the United States. Two incidents in this period should also be mentioned. In March 2014, a standoff occurred between China and the Philippines near Second Thomas shoal. The Philippines was attempting to strengthen a warship it intentionally beached in 1999 on the reef, and China intended to stop this plan. On March 29, with US diplomatic and military support, the Philippines finally resupplied the shoal while abandoning the construction of facilities. During and after this standoff, the United States and China had several direct diplomatic disputes over this issue. US politicians, including President Obama, said to their Chinese counterparts “that the use of force, the use of coercion, the threat of force and other means of intimidation are unacceptable” [47]. China urged the United States to stop taking sides on the issue of sovereignty, making irresponsible remarks, and encouraging the provocative, risky actions of its ally [23].

In early May 2014, a Chinese deep-water drilling rig “Haiyang Shiyou 981” was deployed to the waters of the Paracel Islands to explore and drill for gas. Vietnam responded by sending combat divers and released considerable quantities of fishing nets and bulky obstacles to disturb it. Subsequently, Chinese escort ships engaged the Vietnamese ships to interfere with and confront them in the proximity of 17 nautical miles south of Triton Island. The United States did not provide concrete support to Vietnam but sided with Vietnam diplomatically and in public opinion. The US State Department released a press statement stating that China’s “unilateral action appears to be part of a broader pattern of Chinese behavior to advance its claims over disputed territory in a manner that undermines peace and stability in the region” [44]. Although the United States may think the response soft, China considered the response an unprincipled taking of sides. Besides, despite Vietnam’s unpractical claims, China considers this sea area to be uncontested and that Vietnam’s destruction of the platform operations caused the standoff.

From 2017 to 2020

This period is marked by the Trump administration and its preferences for engaging in competition, changing balance of power, and irregularity in strategic communication; thus, power competition in the SCS has increased to an unprecedented level. While, in this period, the legal challenges and third-party factors are less influential than in the other two periods.

The Trump administration has never considered the SCS as a major agenda item in its foreign policy; issues such as the economy, trade, and North Korea’s nuclear capability have been its priorities. However, “In an international security environment described as one of renewed great power competition, the South China Sea (SCS) has emerged as an arena of US-China strategic competition. U.S.-China strategic competition in the SCS forms an element of the Trump Administration’s more confrontational overall approach toward China, and of the Administration’s efforts for promoting its construct for the Indo-Pacific region, called the Free and Open Indo-Pacific (FOIP)” [11]. The military and strategic establishments strengthened their perception of maritime competition in the 2017 National Security Strategy and 2018 National Defense Strategy, stating bluntly, “China will continue to pursue a military modernization program that seeks Indo-Pacific regional hegemony in the near-term and displacement of the United States to achieve global preeminence in the future” [60].

In the context of Chinese policy, “power competition” is even a negative term. China eschews using the word (although it appears in some passive China–US interactions), hesitating to advance the competition narrative and reiterating the prior policy and rhetoric. However, with its maritime rise, China should logically and by necessity deploy weapons on the islands and reefs and increase its military presence in the SCS. Some of them are normal capacity building and daily patrolling activities, while others target the increasing US military operations in the SCS, which the United States considers China’s new expansion.

China’s increasing power in the SCS is a major concern for United States. As aforementioned, some observers have argued that other issues have been prioritized over the SCS issue while China has been advancing its objectives during this time; thus, “the US is losing control of the South China Sea” [25, 27, 29]. Even top officers have supported this judgment. On April 26, 2018, Admiral Philip Davidson, the then nominee for Indo-Pacific Command, stated at the review hearing of the Senate Armed Services Committee that “China is now capable of controlling the South China Sea in all scenarios, short of war with the United States.”Footnote 2

For several reasons, China–US strategic communication and maritime dialogue are becoming stalled and dysfunctional. The two heads of states have never discussed the SCS issue in formal meetings and the reported phone calls; by contrast, they focus on economic and trade relations and North Korea’s nuclear issues. In 2017, the two sides established the US-China Diplomatic and Security Dialogue (2 + 2) and held two rounds of talks in which the SCS is the core issue; however, the effect of the dialogues was unsatisfactory because both sides were just repeating diplomatic languages. China asked the US not to violate China’s sovereignty over its islands and reefs or to infringe on its security and maritime rights, and the US stressed China not to undermine the freedom of navigation in the SCS or engage in the “militarization” of islands and reefs. More seriously, this dialogue has never been held again since its second round in November 2018. The absence of serious dialogue exacerbates strategic misunderstandings on both sides. The US is more and more anxiety and overaction over China’s rising maritime power; China is increasingly pessimistic about US policy and posits that regardless of China’s restraint, the United States will maintain its pressure on China.

In 2018, the fight between the two sides over the militarization of islands and reefs in the SCS became more acute. In May, China installed anti-ship cruise missiles, surface-to-air missile systems, and jamming equipment on some islands and reefs in the Spratly Islands. Considering that the relevant infrastructure had been completed as early as 2015, the military deployment on these islands and reefs had not proceeded as fast as expected. China may think that it has shown restraint by only deploying what it perceived to be necessary, limited homeland defense facilities, even in the context of the United States intensifying military operations within 12 nautical miles of the islands and reefs. However, the United States viewed it differently and reacted strongly. As an initial response, on May 23, 2018, the Pentagon disinvited the People’s Liberation Army Navy from the 2018 Rim of the Pacific exercise, and on November 9, 2018, the United States for the first time “called on China to withdraw its missile systems from disputed features in the Spratly Islands” [60].

Legal conflict has been a slight drop in temperature. For China, it abandoned taking a new initiative in legal battles because the arbitration was over and the Duterte administration was willing to set aside the Arbitral Award. For the United States, because of frequent withdrawals from the international system and the Trump administration’s principle of “America First,” coupled with the absence of and changes in State Department personnel, its international credibility and expertise on rule and law have been negatively affected, and it has been unable to implement some new legal front, except for repeating the diplomatic rhetoric of the Obama administration and raising its voice to China.

However, a diplomatic war realized in legal battles occurred in 2020. The US Notes to United Nations rejected China’s claims,Footnote 3 and the US Position on Maritime Claims in the South China SeaFootnote 4 brought this conflict to a climax. In these statements, the United States systematically opposes most of China’s claims in Macclesfield Islands and South of Macclesfield Islands waters in the SCS and sides with other claimants on the maritime delimitation and the attribution of some maritime features. The United States deems that it is upholding the rule-based international order, and China deems that the United States is just “stirring up trouble” in the SCS and “breaking the US government’s public commitment of not taking a position on the South China Sea sovereignty issue.”Footnote 5

A new conflict on the rules of the Code of Conduct (COC) is occurring. The United States is questioning China’s attempt to pressure ASEAN to negotiate restrictive conditions on conducting exercises and oil and gas exploration with non-parties of the COC, excluding its presence and interest in the SCS [6, 64]. Additionally, the US is concerned about China increasing its influence through negotiations and is urging ASEAN to reject any proposed guidelines “to be manipulated by the PRC [65].” China has not officially responded to these criticisms, but according to my observations, China resents the US backsliding in the COC negotiations, from supporting to suspecting or even blocking.

Third-party factors have changed such that the United States is increasing its intervention in maritime disputes involving China, while other claimants, such as the Philippines and Malaysia, are more concerned with being involved in the strategic competition between China and the United States and cautions against US movement. The United States is emphasizing how to use the SCS dispute to compete with China rather than responding to the concerns of ASEAN countries. Partly to draw ASEAN countries into the China–US power competition and advance its Indo-Pacific Strategy, the United States tends to take sides and hold China responsible for all the incidents it is involved in, for example, the Vanguard Bank confrontation (2019), Natuna fisheries dispute (2019), and West Capella standoff (2020), even without invitations and calls from other claimants, of which, the collision incident around Paracel Islands on April 2, 2020, is representative of U.S. siding with other claimant: although it occurred 7 nautical miles off woody island and probably involved Vietnamese militias, the State Department said, “This incident is the latest in a long string of PRC actions to assert unlawful maritime claims and disadvantage its Southeast Asian neighbors in the South China Sea” [63] (Table 1).

Table 1 Different factors of different roles in different periods
Full size table

Conclusion

Since 2009, the SCS issue has been a topic of concern of China and the United States and will continue to affect China–US relations in the years to come. I posit that how both parties can manage their differences on this issue will determine whether they could avoid slipping into the “Thucydides trap.”

Based on my analysis, some conclusions are as follows. First, these factors of power competition, disputes over maritime rules, and third parties are the three most important variables that have stimulated the development of China–US conflicts in the SCS. In different periods, different factors play different roles. Third-party factors in 2009–2012, disputes over maritime rules in 2013–2016, and the power competition since 2017 have respectively had the most powerful explanatory power.

Second, China–US competition in the SCS is the result of multiple factors, which usually intertwine and reinforce each other. For instance, regarding the SCS Arbitration, on the one hand, disputes over maritime rules with China pushed the United States to announce its stance on issues such as the nine-dash line. On the other hand, third-party factors were also effective. As an ally of the Philippines, the United States had to support this case. Therefore, sequencing of the roles is comparative, and overemphasizing the role of one of these factors will limit the understanding of the real situation.

Third, these three factors have distinct development logics. Generally, power competition will continue to be the most influential factor and play an increasingly important role for the foreseeable future, while the roles of other factors will decline in relative importance. However, there will also be uncertainties, and some new major incidents, perhaps relating to third parties or disputes over maritime rules, might temporally trigger the development of the two other factors. Considering that the China–US “total competition” over the SCS is a strategic consensus in the United States [12], legal warfare and information warfare are always in constant occurrence.

Fourth, the preferences of different leaders and governments may change the role and order of the three variables in the short term, but the roles of individual leaders should not be exaggerated in the long term, such as in the next 10 years or more. In other words, the China–US conflict over the SCS is determined more by structural factors than by individuals. Under Joe Biden administration, the direction of increased competition will not change, but the pace and approach may differ.

Moreover, China and the United States are also increasingly sensitive and anxious to the development of the situation, which makes the polices and reactions more emotional. When Assistant Secretary Russel was asked what would he would do in the Obama administration if he had the opportunity to re-present on China policy, in his speech at Peking University on December 6, 2019, he mentioned the Scarborough Shoal incident of 2012 and said, “I would advocate direct involvement by sending aircraft carriers.”Footnote 6

Analyzing the past is a guide to the future. This article may improve the understanding of the current stance of China and the United States on the SCS and help both sides be more aware of their differences so that they can successfully manage them.