1. Introduction

This paper examines the motivations for increased US actions in the South China Sea, the evolving security dilemma, and the potential impacts on US-China relations. Initially, it explores the qualitative analyses of the security dilemma from a regional issue between China and Southeast Asian nations to a broader US-China conflict. It then explains the actions of both nations through the lens of realism, assessing whether these actions might foster cooperation or conflict. This is done by considering the frameworks of defensive and offensive realism, the security dilemma, and competitive spirals.

1.1. The Three Phases of U.S. Involvement in the South China Sea

1.1.1. The Pivot to Asia

The first phase, marked by the US's "Pivot to Asia" policy during the Obama administration, redirected American focus from the Middle East and Europe to East and Southeast Asia [1]. This was done in order to counter China's rising influence. This included strengthening economic and military ties with nations such as Vietnam and the Philippines, emphasizing the strategic importance of the South China Sea, and advocating for the peaceful resolution of disputes and freedom of navigation.

1.1.2. Response to the 2016 Arbitration Ruling

The second phase involved bolstering the US presence in response to the 2016 South China Sea arbitration ruling, which found China's claims unsupported by international law. This decision justified the US's enhanced military activities in the region to promote adherence to international law and order.

1.1.3. Diplomatic Efforts and Alliance-Building under the Biden Administration

The third phase saw the United States intensify its diplomatic efforts and alliance-building, particularly under the Biden administration. This was focused on the South China Sea and Taiwan. High-level discussions with Southeast Asian countries and the reinforcement of regional security frameworks like the Quad and AUKUS demonstrate the ongoing strategic importance of the region in US foreign policy.

2. Theoretical analyses under the Realism perspective

The realist perspective on international relations posits that states are rational actors seeking to ensure their own survival and increase their power in relation to other states. This perspective provides a useful framework for analyzing the strategic actions of the United States in the Asia-Pacific region, particularly as they relate to China in the three phases discussed. The realist perspective enables the identification of the rationale behind the actions undertaken in each phase. These actions are responses to the security dilemma between the United States and China. In this context, measures taken by one state to enhance its own security lead to reactions from other states, which in turn lead to tensions and conflict.

2.1. China’s Economic and Military Rise

Over the past few decades, China has experienced unprecedented economic growth and military modernization, in particular, remarkable advances in the areas of defence and high technology. This rise has not only changed the balance of power in the Asian region but has also attracted widespread attention globally. China's economic growth has led to greater international trade and investment, while militarily, China has strengthened its defence capabilities, particularly in missile technology, cyber warfare, and air and space capabilities [2]. In light of China's ascension, the United States has initiated a reassessment of its strategy in Asia. In response to China's growing influence, the U.S. has intensified its military collaboration with traditional Asian allies, including Japan, South Korea, and the Philippines. This has entailed elevated defence spending, enhanced security commitments, the provision of advanced weaponry, and an expansion of joint military exercises. Furthermore, the United States has deployed additional military resources in Asia, including naval forces in the South China Sea, with the objective of ensuring the free navigation and overflight of the region. During the Trump presidency, the United States conducted a greater number of "freedom of navigation operations" in the South China Sea. In May, July, and August 2017, three such operations were conducted in contrast to the same number of operations between October 2015 and January 2017 under the Obama administration [3].

2.2. The Activation of the Security Dilemma

The gathering of these forces has activated the dormant security dilemma between China and the United States in the South China Sea region. Prior to the United States' involvement in the region, the security dilemma in the South China Sea was primarily between China and Southeast Asian countries. However, as China's capabilities have grown and its operations in the South China Sea have expanded, the asymmetry of power between the two has reached unprecedented levels [2]. Consequently, it has become increasingly important for China to demonstrate restraint and reassure its neighbours in order to mitigate or at least limit the security dilemma. Unfortunately, the tendency for more power to reduce the incentive for the powerful to de-escalate (due to the relatively low cost of conflict) is compounded by the fact that it also makes them more reluctant to be restrained, as evidenced by China's actions [4]. China has consistently favoured bilateral solutions to the South China Sea disputes and has consistently objected to the multilateral mechanism for resolving the issue. It took numerous negotiations before China acquiesced to accept the South China Sea Agreement signed with ASEAN, which was signed by the Chinese government. It was only after protracted negotiations that China consented to accept the Declaration of the Parties in the South China Sea, which was signed by ASEAN and established a framework for multilateral cooperation based on the principles of international law [5]. At the same time, it is important to recognize that weaker countries are more sensitive and prone to overreaction, which may result in them taking certain self-defence measures that are perceived as hostile by stronger countries. For instance, during his visit to the Philippines, Barack Obama signed the US-Philippines Enhanced Defence Cooperation Agreement (ECDA), which permits the US military to use five military bases in the Philippines. These actions are regarded by China as a destabilizing factor in the South China Sea issue. A particularly concerning aspect for China is the fact that other countries have formed close alliances with the United States, while the United States has a less cordial relationship with China [6]. This has led China to fear that it may be contained by Southeast Asian countries and external powers.

2.3. The Hegemonic Phenomenon

The phenomenon of hegemony has the potential to exacerbate fears of relative decline and exaggerate perceptions of threat. Consequently, powerful countries may be hypersensitive to any growth in emerging powers [7]. The emergence of China as a naval power and the concomitant rise in its economic bargaining power will undoubtedly increase pressure on the United States, making it difficult for China to reassure the United States. Concurrently, however, the United States and China are likely to believe that their intentions are inherently benevolent. For instance, the United States is convinced that it is merely attempting to guarantee freedom of navigation in the South China Sea, whereas China believes that the issue of the South China Sea is not a matter of international concern [8]. For example, the United States possesses a combination of military, economic, technological, and combined advantages in global influence in comparison to China. The United States is sensitive to and uncomfortable with China's rapid rise, especially as China begins to challenge traditional U.S. influence in certain regions, such as the Asia-Pacific [7]. The United States may be overly sensitive in interpreting China's behaviour as a direct threat to its own hegemonic position. China possesses greater economic and military power than Southeast Asian countries. This asymmetry of power allows China's behaviour, particularly its militarization and territorial claims in the South China Sea, to be perceived as a threat by its neighbours. For these smaller countries, China's assertive policies and military advances may be perceived as hegemonic behaviour, increasing regional instability and tensions.

2.4. U.S. Foreign Policy and Military Alliances

The United States' foreign policy is underpinned by a robust and reliable network of military alliances. President Biden's strategy can be interpreted as a preference for near-term outcomes and myopic decision-making based on prospect theory, which emphasizes the risk-averse tendencies of states in the face of potential losses, as well as the risk-seeking tendencies in the pursuit of potential gains [9]. In the case of policy towards China, it could be argued that Biden is attempting to mitigate the potential losses that the US may suffer in the face of confronting China alone by strengthening alliances and increasing the potential gains from pressure on China through multilateral cooperation. This is also consistent with the perspective of realist theory, which posits that Biden's actions exemplify the typical conduct of power politics. Realist theory postulates that international politics is driven by anarchy and national interests, and that state behaviour is largely determined by their needs for power and security [10]. The formation of a military alliance with the objective of counterbalancing China, such as AUKUS, represents a significant leap in Australia's military capabilities [9]. However, it also carries the potential for the security dilemma in the Indo-Pacific and South China Sea region to evolve into a military spiral of competition. ASEAN countries will experience an immediate increase in military capabilities and an elevated probability of the South China Sea dispute evolving into an arms race between major powers. Biden has demonstrated a strategy of utilizing collaboration within the framework of international law to enhance the United States' position and influence in global politics, and the 2016 South China Sea arbitration case provides some legitimacy for this course of action.

3. The Implication of the Relationship between the US and China

The Office of the Director of National Intelligence (ODNI), which is responsible for the U.S. intelligence system, has released its Threat Assessment Report 2021, which focuses on the "most immediate and serious threats" to the U.S. The United States identifies China as a future threat, citing the country's growing economic, military, and technological capabilities as a potential challenge to the United States [11]. China is becoming an "evenly matched" competitor with the United States, challenging the United States on multiple fronts: economically, militarily, and technologically. China competes with the United States on all fronts, including technology, influence, diplomacy, security, values, and the economy.

3.1. Mistrust and Fear in the Security Dilemma

Long-standing security concerns are brought to the fore by the concentration of military power, while other less contentious security issues are intensified by mistrust and fear between states (due to anarchy, states are unable to fully trust each other's intentions). The United States perceives China's actions in the South China Sea as a threat, a perception that China views as malevolent. Given that states are prone to exaggerating the hostility of the other, they may perceive the other as an intentional threat even if that is not the case [10]. If the other is merely a genuine security-seeker taking some precautions, as in the case of the United States and the Soviet Union competing with each other to bolster their nuclear arsenals during the Cold War due to deep mistrust and fear, then it is possible to view their actions in a different light. Such behaviour did not stem from direct hostility but was based on precautions against potential threats from the other side. Each side feared that the other might be the first to use nuclear weapons, and thus became trapped in a vicious security dilemma and arms race, despite the fact that they might actually both prefer to avoid direct conflict. Consequently, a state may fail to recognize that it is already engaged in a security dilemma with another state, and thus fail to recognize the necessity to take measures to demonstrate good intentions and reassure others, which undoubtedly deepens the security dilemma on both sides [12]. The policy of NATO's eastward expansion, which is perceived by Russia as a threat to Western power, has led Russia to increase its military presence in neighbouring countries. Such actions have further exacerbated tensions on the European continent, making it difficult for both sides to take measures to reduce antagonism. In such deep security dilemmas, one or both sides may feel compelled to take more aggressive security measures due to extreme fear [12]. Relations between the United States and Iran are then often caught in a vicious cycle of misunderstanding and mutual distrust. When the intentions of both sides change from benevolent to malevolent, the security dilemma evolves into a spiral pattern that obstructs normal interaction and initiates a vicious cycle. At this juncture, the security dilemma transforms into a security spiral.

3.2. Mistrust in U.S.-China Relations

In the case of the South China Sea, even if China or the United States takes costly measures to demonstrate their benevolent intentions, these actions may still be misunderstood or distrusted by the other side. China demonstrates its commitment to regional stability by limiting certain military exercises, while the United States may continue to conduct "freedom of navigation operations" to demonstrate its support for freedom of navigation in international waters. However, these initiatives are often seen by the other side as strategic manoeuvres rather than confidence-building steps.

This cycle of mistrust is particularly pronounced in U.S.-China relations, where the South China Sea has become a symbol of confrontation between the two countries. The United States' response to China's construction of islands in the South China Sea and its militarization demonstrates the United States' deep concern about the security situation in this region. China, on the other hand, views the United States' actions as a manifestation of interference in its national sovereignty and regional security. Even if these actions are motivated by a demonstration of national defence intentions and the preservation of regional rights and interests, in an environment where adequate communication and trust-building are lacking, the good intentions of both sides are often perceived as strategic confrontation, further exacerbating the security dilemma between the United States and China.

4. Conclusion

From a realist standpoint, the US's policies in the South China Sea are shaped by both "interest-orientation" and "threat-orientation." The US views China's island building, naval enhancements, and increasing influence in regional negotiations as potential threats to the existing power balance in the Western Pacific, prompting concerns over its dominance in the area. This has led the US to intensify its presence, particularly through frequent patrols around the Spratly and Paracel Islands, emphasizing principles like innocent passage and freedom of navigation without overtly contesting China's claims.

China, for its part, has handled the situation with caution, resorting mainly to diplomatic protests while upholding the principle of navigation freedom. This cautious approach reflects a complex interplay of reassessing power dynamics and intentions, portraying the South China Sea not only as a geopolitical arena but also as a test of international law and regional cooperation ethos.

Both nations are engaged in a strategic game that significantly influences their future regional and global standings. In light of this, both the US and China need to make strategic and cognitive adjustments. The US should recognize that its military activities might be seen by China as sovereignty threats, while China should understand that its militarization efforts raise regional tensions and prompt US intervention. To mitigate these tensions and misunderstandings, transparent and constructive dialogue between the two is crucial to avoid exacerbating the security dilemma.