The South China Sea for China, the United States, and what choice for Vietnam

Abstract Although it is not the most significant feature on the strategic map of the United States, it is firmly in favor of the South China Sea, maintaining its status as an area of international waters for the foreseeable future. It will allow for the unimpeded passage of cruise ships and commercial transport vessels. Even though the United States and China are the two actors with the most influence on the political situation in the South China Sea, and even though Vietnam is an indispensable subject in this area, the strategic interests of the United States and China are considered to be crucial for each country. Vietnam is an indispensable subject in this area. Because the South China Sea is so strategically important to China, the United States, and Vietnam, it is likely that these three countries will come into conflict over it shortly. Which political maneuvers and decisions on the part of these two global superpowers affect the current situation in the South China Sea? Moreover, what other options does Vietnam have when it comes to those behaviors?


PUBLIC INTEREST STATEMENT
While its location in the south of China is generally understood, "South China Sea" as a name often leads to the mistaken belief that the sea is Chinese territory China has repeatedly taken actions that have destabilized the South China Sea region. Which is possibly due to growing the world's second-largest GDP and thus realizing the "Chinese dream". These moves by China cause concern for the ASEAN territory and endanger free passage and legitimate trade in the world's second busiest shipping lane. The United States who cannot support China's current actions have made increasingly drastic statements and actions in the South China Sea to prevent China's abuses.Many nations worldwide, including those in ASEAN where Vietnam holds a particularly pivotal position, support the United States' position.To avoid a conflict with China and win the support of the United States and other countries, Vietnam has opted for a measure of "defensive realism," in its view.

Introduction
The South China Sea located east of Vietnam connects the Pacific and Indian Oceans and stretches from Singapore and the Malacca Strait to the Taiwan Strait. Several Asian countries claim sovereignty over various parts of a marine area which encompasses 3,500,000 km 2 (Koda, 2016), including a chain of uninhabited islands and reefs. (Vietnam calls this area Bien Dong-East Sea, while many countries call the South China Sea). 1 As the second-busiest global shipping lane, The South China Sea has geopolitical significance and more than 50% of annual global trade of passes through the Strait of Malacca, Strait of Sunda, and Strait of Lombok. Every day, more than 1.6 million m 3 (10 million barrels) of crude oil is transported through the Strait of Malacca. Together with liquified gas, the volume of fuel transported through the Strait of Malacca is three times that of the Suez Canal and five times that of the Panama Canal (GlobalSecurity, 2021). In addition, the region has proven oil reserves of about 1.2 km 3 (7.7 billion barrels), out of an estimated total of 4.5 km 3 (28 billion barrels). Natural gas reserves are estimated at 7,500 km 3 . 2 While these estimates are significant, especially for gas, they are still rather minor on a global scale; for gas, this equates only to about 3% of world resources. China, on the other hand, has estimated higher levels of undiscovered resources, but these have not been independently verified (Rahman, 2022, p. 360). The Strait of Malacca, which flows between Indonesia, Malaysia, and Singapore, connects the Indian Ocean with the Pacific Ocean through the South China Sea. It is the shortest sea route between Persian Gulf suppliers and key Asian markets (Villar & Hamilton, 2017).
The South China Sea plays a crucial role in China's strategic competition with the US (Fels & Truong-Minh, 2016;Zhou, 2015). Strategically located, it has a geographical structure of no other sea area adjacent to China and is therefore vital to China's modern navy. Control of the South China Sea is a prerequisite for the future development and modernization of China's navy and aerospace industry (Garcia, 2019;Morton, 2016;Rahman & Tsamenyi, 2010). However, the activities of China impact the balance of power in the South China Sea and threaten the security and stability of the Asia-Pacific region (Mearsheimer, 2010;Sơn, 2014).
Relatively unimportant strategically to US mapping, the South China Sea has never been a US concern. It is, however, included in the East Asia strategy, which includes the US, the Korean Peninsula, and Japan (Qingchuan, 2011). The US wants the South China Sea to remain an international sea to ensure that military and commercial ships travel freely and unrestricted. The US realizes, however, that if they do not exert influence in the region, Japan and China will use the opportunity to protect their own trade and maritime routes by using military power to control the sea (Anh, 2009).
Currently, China considers the South China Sea as one of its core interests (Group, International Crisis, 2021) alongside Taiwan, Tibet, and Xinjiang (Lee, 2017;Toshi & Holmes, 2011). For its part, the US believes that the South China Sea is crucial not only to those countries directly bordering its territorial waters, but to all countries with security and economic interests in Asia (Cường, 2011;Hossain, 2013). China's core interests seem to align with what the United States considers, it is vital national security interests of the US, with the implication that both countries are willing to act on these interests. Competition and conflicts between the two countries are difficult to avoid due to military, political and economic influences. In particular, China's rapidly growing economic development is becoming a determining factor for the strategic environment in Asia and global security. Given its global strategic importance outlined above, the South China Sea then is a key arena of competition between the US and China.
Vietnam has a coastline comprising about 3260 km, around one km of coastline for every 100 km2 of territory, a rate six times higher than the world average. No place on the Vietnamese mainland is more than 500 km from the coast and its seas and continental shelf are part of the South China Sea. Vietnam has large internal waters, a territorial sea, a contiguous zone, an exclusive economic area, and a continental shelf, according to the 1982 United Nations Convention on the Law of the Sea. Vietnam has thousands of large and small near and off-shore islands, In addition, it claims the whole of the Spratly and Paracel areas (Hoang Sa and Truong Sa), located in the center of the South China Sea. Consequently, the South China Sea issue has significant importance: it is closely related to Vietnam's situation, security, politics, and socioeconomic development (Mau, 2014;Nam, 2020;Pho Hoang Han, 2007). Southeast Asian littoral states, like Vietnam without alternative routes, and the straits states, are most dependent upon these Sea Lanes of Communication (SLOC) such as the South China Sea. It facilitates a range of national trade for Southeast Asian Littoral states: from 86% in Vietnam, to 58% in Malaysia (Rahman, 2022, p. 358). Various states have been asserting more strongly their claims to contested waters and island chains in the South China in response to China's increasing dominance and the growing involvement of the United States and its allies. Vietnam, a major claimant state, plays an important role in the dispute (Group, 2021). Therefore, in the face of calculations and actions of great powers such as the US and China in the South China Sea, Vietnam must choose the most appropriate means through its foreign policy to ensure its sovereignty and the interests of the Vietnamese people.
Numerous works contain research on the South China Sea issue, including the calculations and disputes between major powers and ASEAN nations. For instance, between the United States and China regarding the South China Sea, there are works such as (Mearsheimer, 2010;Cường, 2011;Qingchuan, 2011;Toshi & Holmes, 2011;Cronin, 2012;Hossain, 2013;McDevitt, 2014;Tabbasum & Sobea, 2014;Mosyakov, 2015;Zhou, 2015;Morton, 2016;Cường, 2017;Scott, 2018;Zhao, 2018;N. A. Cường et al., 2020;A. A. Vuving, 2020;Wiegand, 2020), or Vietnam with related subjects to other agencies are China, the U.S., or ASEAN with works such as: (Blazevic, 2012;Group, 2021;Le Hong, 2013;Manyin, 2014;Tønnesson, 2000). However, a direct examination of the conflict between China and the United States to explain Vietnam's behavior on the South China Sea issue has yet to receive sufficient consideration. Therefore, incorporating the historical method into the space of direct interaction between the actors directly involved in the South China Sea, namely China, the United States, and Vietnam, this article intends to provide a systematic approach to the evolution of the South China Sea conflict process. In addition, the article relies on empirical analysis, realism, and policy provisions of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) to partially answer questions such as: How do the United States and China influence the South China Sea issue? What options does Vietnam have for responding to these actions? How have the historical interactions between the three nations, and the separate influences of the US and China lead to Vietnam's response strategies regarding the South China Sea.

China's calculations
China is adopting a strategy combining consolidation of naval power with balancing national interests: It considers its right to become a maritime power against maintenance of regional stability by acting on pragmatic calculations to cooperate with neighboring countries and the US. By testing the limits of its ability to control maritime features and disputed waters through its growing military might, China is trying to build a maritime order in Southeast Asia and the Chinacentric South China Sea through long-term maritime strategy and ambition. China's aggressive reclamation and building of geographical features in the South China Sea in recent times is clearly within this goal.
First, China wants to accelerate its maritime power strategy launched officially at the 18th National Congress of the Communist Party of China in 2012 (Cigui, 2012). A maritime strategy with Chinese characteristics will be able to protect national territorial sovereignty, maritime interests, and security of the state and ensure economic and social development. (Hoành, 2015) One of the crucial parts of the strategy is the need to build military bases on artificial islands so that China can control the vast South China Sea area. Through land reclamation China aims to build control points, logistics, and strong bases for deploying a variety of military and non-military ships, aircraft, and unmanned aerial vehicles (UAV) to control the South China Sea area. (A. L. A. L. Vuving, 2010) Second, China wants gradually assert an irrational claim about its "nine-dash line" (Tsirbas, 2016) which aims to recover all the geographical features in the Paracel Islands and the Spratlys Islands claim (Lokshin, 2015). China rushes to strengthen and expand military bases to demonstrate that it is controlling the disputed areas, and subsequently by also creating favorable public opinion, legitimize the claim. 3 Third, China wants to create the status quo in its favor. The development of a code of conduct (COC) between ASEAN and China is underway but little progress has been made. Therefore, China strengthens actual control on the ground in the South China Sea, and takes advantage of the COC negotiation process as well as other bilateral negotiations. (Trung, 2016) Article 5 of the Declaration on Conduct of the Parties in the South China Sea-DOC in 2012 stipulates: "The Parties undertake to exercise self-restraint in the conduct of activities that would complicate or escalate disputes and affect peace and stability including, among others, refraining from action of inhabiting on the presently uninhabited islands, reefs, shoals, cays, and other features and to handle their differences in a constructive manner." 4 To create a new status quo, China has turned geographical features of low tide elevation or lowlying lowlands into islands and following Article 121 of UNCLOS 1982 claim the areas. The sea is sovereign with sovereign rights but the International Court has issued rulings on the legal status of geographical features in the Spratlys that are unfavorable to China. After the arbitral tribunal's ruling on the case between the Philippines and China related to the South China Sea, on 12 July 2016, 5 the Chinese leader stated at the summit between this country and ASEAN, organized by the People's Republic of China in Laos on 7 September 2016. This statement refers to the goal of concluding negotiations in the first half of 2017 to quickly finalize a Code of Conduct in the South China Sea (COC). However, so far, this goal has yet to be achieved. The focus of China's actions is to exclude non-regional countries from decisions regarding the COC. In addition, China is increasing pressure to prevent coastal states from engaging in military exercises or developing undersea resources with countries outside the region. The origin of the problems in the South China Sea lies in the territorial disputes between countries that border the sea. If China ignores the arbitration award and unilaterally changes the status quo, the South China Sea will be governed by force rather than the rule of law (Zhao, 2018).
Fourth, China wants to create a China-centric economic cooperation area, with the ambition to replace the role of the US in the Asia-Pacific region. (Akbar, 2019) Launching the BRI to economic, cultural, and political cooperation worth trillions of dollars with the participation and response of Central Asian countries, the Middle East, and some Southeast Asian countries such as Thailand and Cambodia because of the economic benefits and infrastructure this project brings. Meanwhile, Japan, India, and some other ASEAN countries like Singapore are wary of China's ambitions (Vũ, 2017). There is still a continuing debate about whether China's BRI is a noose, drawing the countries participating in the program to become more and more dependent on China, with a public debt trap, forcing these countries to share major ports and resource-rich areas with China. (Brautigam, 2020)

China in action
Since 2014, China has carried out many activities in the South China Sea-building military bases on the islands, firmly equipping itself economically, and claiming territorial sovereignty. In 2014, China was the first country to carry out large-scale reclamation of features such as reefs under its possession. The Spratly Islands, an area of sovereignty disputes between China and other countries (Vietnam, the Philippines, Malaysia, Taiwan, and Brunei), into artificial islands with an area as large as the natural islands. 6 By early March 2015, China had carried out large-scale reclamation and expansion of six of seven reefs under its control in the archipelago into artificial islands. In 1988-1995, seven small natural rocks and reefs were occupied by China. Some were seized by force (Johnson Reef) from the Vietnamese navy during the 1988 Truong Sa naval battle, and are all subject to sovereignty disputes between China and three other countries (Philippines, Taiwan, Vietnam). By February 2015, China's artificial island-building activities expanded, including the Subi Reef area. 7 (Ngọc, 2014) By 2018, after the accretion of artificial islands on the Spratly archipelago, the total area of artificial islands occupied by China has reached about 13.21 km2 (mainly concentrated on three rocks named Mischief, Subi and Fiery Cross). 8 In addition, China is constantly militarizing the sandbars or rocks it occupies by building airstrips that can accommodate strategic bombers, developing air defense capabilities and air defense observation (radar), and constructing port infrastructure. In May 2018, for the first time, China's H6K strategic bomber, capable of carrying nuclear warheads, took off and landed on Woody Island in the Paracel Islands to demonstrate its control of this archipelago. (Bình, 2018) Previously, in April 2018, China deployed surface-to-sea and surface-to-air missiles on artificial islands in the South China Sea, including Fiery Cross Reef, Subi Reef and Mischief Reef, which are currently under intensive reclamation and militarization. (Shugart, 2016) After reclamation of geographical structures, China continues infrastructure construction activities to realize the strategic goal of controlling the South China Sea area. In 2019, China repeatedly sent military transport planes to Mischief Reef, installed advanced jamming equipment on Mischief and Fiery Cross islands, and deployed surface-to-air missiles and anti-ship cruise missiles on some illegal artificial islands in Spratlys and the Paracel archipelagoes (Minh, 2020). China is calculating and probing the establishment of an air defense identification zone (ADIZ) (Koda, 2016), a matter of great concern. The proposed ADIZ covers the Pratas archipelago in the north of the South China Sea, and the Spratly and the Paracel archipelagoes (A. A. Vuving, 2020;Boquet, 2017). If these activities occur, China will surely face more fierce opposition and resistance from Vietnam and other countries with sovereignty claims over the Spratly Islands who will appeal more strongly to the international community, making the situation more complicated and unpredictable.
China's reclamation activities were conducted over a short time, but they reflect their long-term strategic goals (Wirtz, 2017). This harms the balance of power in the South China Sea and threatens the security and stability of the Asia-Pacific region. Predictably, over the next two decades China will expand its bases in the South China Sea to control the first island chain (Friedberg, 2018) pushing the US out of the region. In the 1982 Law of the Sea Convention, provisions for exclusive economic zones (EEZs) and continental shelves effectively encouraged the occupation by entities of territorial features in order to assert rights to the marine resources found in these jurisdictions. As a result, all such claims overlap with China's and Taiwan's ninedash line claims (Rahman, 2022, p. 361). Legally, China's activities violate Vietnam's sovereignty over the Spratly and Paracel Islands, violate its regional commitments, and violate other provisions of international law (Agusman & Yuda Nur Fatihah, 2020;magazine, Vietnam Law and Legal Forum, 2022).
China continues to be the subject of conflict with ASEAN nations in the South China Sea. China has pushed harder than ever before to expand its sphere of influence throughout Asia (Singer, 2020). Instead of abandoning the policy of "resolutely not taking the lead" in world affairs and "hiding oneself and waiting for openings" during the Deng Xiaoping era, China under President Xi Jinping has adopted intentional aggression. By using a combination of different methods, China seeks to balance its interests with those of the US, contains Japan and South Korea, keeps ASEAN within its sphere of influence, and involves Russia. Simultaneously, China seeks to minimize its resonance from many hot spots, continuing to control the South China Sea disputes to avoid adverse consequences for the strategic goals that China has set. (Linh, 2017) As for the South China Sea issues, although China knows its actions are not aligned with international law, it still wants to proceed with its actions (Strating, 2022), because: "China does this to make sure that its 'nodes and networks are the primary ones through which capital, material, and people in the South China Sea must flow." (Ming, 2015) 3. The South China Sea for the US

Reality and statements
On 10 July 2014, the US Senate unanimously passed Resolution No. S.Res.412 9 on the South China Sea. This resolution affirms the US right to freedom of navigation and the use of seas and airspace in the Asia-Pacific region under international law. It considers that China's territorial claims and actions are unjustifiable under international law as articulated in UNCLOS; and that these actions constitute a unilateral attempt to change to the status quo by force; and that these claims and actions are in violation of The DOC that China signed with ASEAN in 2002. The resolution also urges the Chinese government to withdraw the Hai Duong-981 oil rig and its forces from their current positions in Vietnam's sea and immediately return everything to the status quo before 1 May 2014.
In 2015, as outlined above, China continued to complicate the South China Sea situation. China's intensifying reclamation activities, reinforcing artificial islands, and construction on islands. The islands and reefs in the area illegally occupied by China have been expanded and fortified, creating conditions for forming a maritime defense network and controlling the world's shipping trade in the South China Sea. (Watkins, 2015) China remains uncompromising on sovereignty and continues strengthening its ability to exercise de facto control over disputed areas and advance claims. Moreover, they deftly place their claims below the threshold of conflict with the United States. China conducts harassment against US Navy ships operating in the South China Sea, warns military aircraft to stay away from its artificial islands, and conducts overt intimidation activities against its Philippine and Vietnamese neighbors.
In response to those actions of China, the US has carried out drastic activities to China's increasing clear claims. On 27 October 2015, the destroyer USS Lassen armed with the direction missiles of the US Navy and reconnaissance entered within 12 nautical miles of the artificial island that China illegally built at Subi Reef, in the Spratly Islands. 10 This event that marks the beginning of the US challenge to China's sovereignty claims over the illegally reclaimed and artificially built islands. It also comprises the most determined and forceful action taken by the US in its involvement in South China Sea issues.
During this action of the US armed forces, US Defense Secretary Ashton Carter warned the Senate Armed Services Committee that the US military would continue its mission to approach China's illegal artificial islands (Quyên, 2015). Subsequently, on the night of November 8 and 9, 2015, two US B-52 strategic bombers flew close to these artificial islands. "The B-52s were on routine missions in the South China Sea", and took off and returned to Guam when the mission was over, Pentagon spokesman Bill Urban told Reuters. According to Urban, China's ground forces made efforts to contact the bombers, but they continued their mission. (Torbati & Alexander, 2015) To clarify these actions, then US President Barack Obama while attending the G-20 Summit gave a sideline speech at the University of Queensland in Brisbane, Australia, on 15 November 2015: "We believe that nations and peoples have the right to live in security and peace. That an effective security order for Asia must be based-not on spheres of influence, or coercion, or intimidation where big nations bully the small-but on alliances of mutual security, international law, and international norms that are upheld, and the peaceful resolution of disputes." Obama further advocated: "We will support ASEAN's effort to reach a code of conduct with China that reinforces international law in the South China Sea." (House, The White, 2014) Immediately afterward, on 21 November 2015, to reinforce the commitment of support to Southeast Asian countries, speaking before the meeting between the US and the leaders of 10 ASEAN countries, US President Barack Obama said he commended ASEAN for working to create a code of conduct for the South China Sea "including the peaceful resolution of disputes, freedom of navigation and freedom of overflight." In this way the United States has shown determination to join with countries, especially America's allies in the Asia-Pacific region to bring more pressure to bear on China whose actions challenge international law, infringe on the sovereignty of many countries in the South China Sea area, and challenge US interests.

Realize the claims
During the next, Washington's policy under President Obama's government was to continue to send US naval warships through the area and to ignore the so-called "no-fly zone" that Beijing declared. In reality, however, the United States did not have a clear policy to prevent or at least limit China's blatant occupation and construction of military outposts on the sands and reefs in the South China Sea. In addition, they missed the opportunity to speak out more emphatically on the illegality of China's self-recognition of territorial sovereignty by demanding that China implement the international arbitral tribunal's ruling in July 2016. Hence, US strategy in the South China Sea needs to be clarified and has been dismissed as a focus of the Obama administration's Asia-Pacific orientation. President Obama announced in the 2015 National Security Strategy that the US strategy to deal with China is not strong enough and is not a priority in the Asia-Pacific rebalancing policy. 11 After taking office as the 45th President of the United States, Donald Trump has made powerful and more drastic moves than his predecessor. US President Donald Trump unveiled a new National Security Strategy, outlining the foundation and priorities that will guide US foreign policy during his term. In the pillar of "advancing American influence," Trump repeatedly referred to China as a "rival power" that is "challenging the power, influence, and interests of the United States, seeking to undermine security and prosperity of the United States." China became a crucial target of the Trump administration's priority of protecting economic security, and the US strategy has repeatedly referred to its "abusive" trade practices (Alexandra Jingsi, 2020). President Trump has shifted America from the Pivot to Asia strategy to the Indo-Pacific strategy which promotes defense cooperation with countries in the region and ensures security in an ocean area stretching from the Japan Sea to the Indian Ocean. The US pledged to support close allies to maintain superior military power and deter attacks against other countries to dominate and control the entire region, preventing countries in the area from challenging the US leadership role. (Saha, 2020;Scott, 2018).
On 30 September 2018, the incident between Chinese and US ships further pushed the US to assert its presence in the South China Sea, especially with the US resumption of the Freedom of Navigation Operations (FONOP) activities in waters claimed by Beijing (Xiaobo, 2019). In 2018, Washington withdrew its invitation to China to participate in the Rim of the Pacific naval exercise (RIMPAC) -a joint exercise hosted by the US, with more than 20 countries. Two years before, the US had invited China to join this exercise as a sign of openness. The US also continued its strategy of drawing closer to countries in the region dealing with China's actions, especially Vietnam and the Philippines (Eckstein, 2018).
In 2019, the US undertook many practical activities such as augmenting patrols in the South China Sea to maintain international freedom of navigation and overflight, thus increasing strategic competition with China in the region. The US proposals and activities in the South China Sea have been deployed on the basis of new policy of the President Trump administration. The US promotes freedom of navigation operations, and US legal diplomacy supports maritime security and assists ASEAN countries in negotiating a Code of Conduct in the South China Sea with China. The US has repeatedly sent warships close to some illegal artificial islands following its freedom of navigation operations strategy. In 2020, the US influenced and conducts militarization in the South China Sea. The administration of President Donald Trump did not back down from pressure from China. The US Navy has continued to send aircraft and warships close to the illegal artificial islands that China built to challenge China's unreasonable sovereignty claims in the South China Sea. Along with field activities and diplomatic statements, the US strengthens relations with close allies in the region such as Japan, Australia, the Philippines, and Thailand to find ways to restrain and prevent unlawful activities of China. 12 There is a unity of purpose among US power agencies, which is to protect international rules and standards-the basis for creating the liberal world order led by the US. In reality, however, China had formed for them the initiative in this area. As long as the US neglects the South China Sea issue, China will take the opportunity to act strongly. In 2017 the Korean missile crisis became the most prominent US issue in Asia and "shadowed" many other points of dispute, including the South China Sea issue. North Korea's nuclear and missile crisis had become a top foreign policy priority of the Trump administration. The United States views Pyongyang's nuclear and missile programs as a clear and visible threat to its mainland. And so, 2017 became the year the disputes in the South China Sea were "forgotten." This facilitated the conditions for China to promote military buildup in the waters it claimed and appease the countries' dispute.
During the administration of Barack Obama, China's militarization of the South China Sea accelerated. While the US was inattentive and mired in wars in the Middle East, Xi Jinping was more resolute, and bolder. The 2015 Chinese Defense White Paper did not explain Beijing's blatant plot to change the status quo in the South China Sea, creating a stronger position for itself on the "leverage" of disputes in this area. In 18 months, however, China has reclaimed more than 2,000 acres of submerged islands and atolls in the South China Sea, leading to a tense situation in the region (Singh,). To test the limits of its ability to control maritime features and disputed waters through its growing military power, China is attempting to render the East and South China Seas China-centric. China's actions have opened the door for the US to enter the region, allowing the US to strengthen its position in Southeast Asia and the Asia-Pacific region in general. Distrust of China's policy has prompted neighboring countries to seek US support. Balancing with China, the US encircled China by forming a special relationship with the Philippines, Vietnam, and Myanmar, becoming a key country in Southeast Asia. (Mosyakov, 2015) The Obama administration initiated the Pivot to Asia strategy to deal with China. When China showed discontent in the South China Sea, the US and Australian militaries later joined the exercise with the Philippine military. This sent a message that no state should infringe on the Philippines sovereignty because to do so means an affront also to US and its allies. 13 However, in general, the "pivot" of the Obama administration has not displayed substance and strength.
By the time of the Trump presidency, the "pivot strategy" was repackaged into a "free and open Indo-Pacific" strategy (FOIP). Accompanied by many substantial moves, especially with respect to the military and economy (e.g. the trade war with China) have caused China to be cautious and deliberate in its actions. (Wiegand, 2020) Under President Biden, the trend of US-China confrontation continues, along with the adoption of the Trump administration's FOIP strategy, although there may be adjustments in implementation. State Department statements also represent consistent policy over both presidential administrations. The U.S. position under Biden supports the conclusions of the 2016 South China Sea Arbitration Tribunal on China's unwarranted claims in areas within the exclusive economic zone or continental shelf of the Philippines. The statement of 11 July 2021, by the U.S. Department of State, reaffirmed this position. Using the same language as his predecessor, Mr. Blinken said: "Nowhere is the rules-based maritime order under greater threat than in the South China Sea." The US secretary of state observed that "China continues to coerce and intimidate Southeast Asian coastal states, threatening freedom of navigation in this critical global throughway". And issued an appeal: "We urge China to abide by its obligations under international law, stop its aggressive behavior, and take steps to assure the international community that China respects respecting the rules-based maritime order, respecting the rights of all nations, large or small." Reconfirming the policy made since 13 July 2020, regarding maritime claims in the South China Sea, Secretary of State, Blinken, referred to the initial statement of his predecessor Mike Pompeo: "We also reaffirm that an armed attack on Philippine armed forces, public vessels, or aircraft in the South China Sea would invoke U.S. mutual defense commitments under Article IV of the 1951 U.S.-Philippines Mutual Defense Treaty." (Blinken, 2021) The United States has a crucial role in ensuring "free and open" access to the South China Sea. If necessary, Vietnam will be an "indispensable partner" in that endeavor (Dy, 2021). However, even if the US role and policy regarding the South China Sea, as outlined above, continue to be maintained, their practical implementation by the new US administration is yet to be evaluated.

Vietnam's choice
According to the analysis presented above China will likely continue to promote the construction of bases in the South China Sea to push the United States out of the region. Importantly within the next two decades, China will continue to violate Vietnam's sovereignty over the South China Sea with two archipelagos, Truong Sa (Spratly Islands) and Hoang Sa (Paracel Islands). On the other hand, the U.S. side is becoming increasingly conscious of its critical role in ensuring that the South China Sea region is genuinely free and open, so Vietnam will be a partner with whom they must maintain close ties. Vietnam's claim to sovereignty over the Spratly and Paracel Islands is, therefore, in the first place for Vietnam's benefit, but it is also a hindrance to China's ambitions and advantageous to the United States. Consequently, Vietnam's relations with China and the United States are complicated. How should Vietnam, therefore, decide? The following analysis will provide some insight into Vietnam's behavior.
In the term 2014 to now, China has carried out many activities in the South China Sea-building military bases on the islands, firmly equipping the economy, and claiming territorial sovereignty. The actions of China above have seriously violated the sovereignty of relevant parties in this area, violated international law, and violated the DOC. China unilaterally prohibited the right to exploit marine resources and destroyed the environment and marine ecology, complicating the situation, and threatening the security and safety of navigation in the South China Sea, seriously affecting peace and stability in the region and the world. Therefore, this action of China has faced fierce opposition from Vietnam, the Philippines, etc. And a strong reaction from ASEAN and the international community, especially the US and other major countries. 14 (Wiegand, 2020) Meanwhile, as outlined above, the US's attitudes, statements, and actions on the South China Sea issue are not enough to prevent China's activities. Moreover, for a long time (at least from 2009 to 2018), the United States did not have a clear, drastic policy and action to prevent or limit China's conduct. The country blatantly occupied, reclamped, filled, and built military outposts on sand and reefs in the South China Sea.
Faced with the reality and the calculations taking place in the South China Sea, Vietnam is carefully considering its options, especially in its relationship with the major powers in the disputes in the South China Sea. Historically, a "hard mechanism" in the form of a military alliance, whereby countries are constrained by a commitment to protect each other's security against a threat from a third party like in the Cold War, has not been an option for Vietnam. By contrast, a "soft mechanism" expressed in the strategic dialogue on security defense or practical models of naval cooperation between Vietnam and countries such as the US and India in recent times has been considered more feasible. Moreover, Vietnam is implementing a multilateral and open foreign policy that makes Vietnam reliable in the international community, and as a result holds many important positions in international politics as a non-permanent member of the Association of Southeast Asian Nations and in the United Nations Security Council 2008Council -2009Council , 2020Council -2021 Vietnam has membership of 63 international organizations and relates with more than 500 NGOs. Vietnam has been active with its increasing role at the United Nations (member of ECOSOC, member of the Executive Council of UNDP, UNFPA, and UPU. . .), promoting its active membership in the movement, association, the Community of French-speaking countries, ASEAN. . . (Affairs 2020) Vietnam's position and influence are constantly enhanced (Cường, 2022).
Vietnam's handling is in bilateral development in the partnership, and multilateral expansion in a collective security mechanism framework, mainly in ASEAN's playing field. Vietnam is in a crucial position, both directly influencing its interests and can play a role in promoting or limiting conflicts in the South China Sea to a relative extent. Therefore, Vietnam needs to be very clear and transparent in bilateral and multilateral relations and take the initiative in making policies and strategies to react to complicated changes in the region. (Aoyama, 2016) There are three options that Vietnam can apply. The first is balancing, the second is concessions, and the third is defensive realism.
First, balancing. In world politics, counterbalance is the conditioning of one country in balance with that of another. Although Vietnam is too weak to challenge directly any major country in the region, Vietnam can still indirectly create a balance by linking with the US and other allies in the area and gradually separating from China. However, there are two main reasons why it is difficult for Vietnam to implement this strategy. The first is because of its close relationship with China. Since 1991, Vietnam has maintained its defense policy of "three nos," avoiding alliances that may cause objections from China. (N.A. Cường & Thành, 2018) In 2019, Vietnam advocated the development of a "four nos" 15 defense strategy. In the circumstances, a counterbalancing might make China think its sphere of influence is decreasing in Vietnam. Thus, China's might intensify illegal drastic activities against Vietnam in the South China Sea (Grossman, 2020, vii). The second reason is that Vietnam lacks a reliable ally to counterbalance China. Only the US and Japan are suitable options (Manyin, 2014).
Under the Trump Administration, however, the US was less concerned with international affairs such as its relationship with Southeast Asian countries and was more focused on dealing with issues that affect US interests and roles, such as the nuclear crisis in North Korea (Cát, 2018). Although under the Biden administration, international issues have been resolved more harmoniously, with both the interests of the United States and its allies, all of America's actions in the South China Sea remain consistent with actions and statements similar to the previous administration. Japan is a suitable ally because it conflicts with China at sea, but it does not have the power to engage in military disputes (Manyin, 2014). In any case, pursuing a strategy of "counterbalance" with China will go against Vietnam's statement about the policy of resolving conflicts in the South China Sea peacefully based on rules and international law. Therefore, Vietnam may not wish to abandon this policy to pursue an unfeasible "counterbalance" strategy.
Second, make concessions. The second option, quite the opposite of "counterbalance," is to reduce relations with the US and move closer to China, and make more concessions to China in the South China Sea disputes. However, this option is not feasible, firstly because joint sovereignty over the South China Sea is a core issue for Vietnam (Group 2021) and conceding will seriously threaten Vietnam's security. Simultaneously, it facilitates more forceful actions by China in the South China Sea. Secondly, anti-Chinese sentiment in Vietnam is vigorous, therefore if Vietnam compromises with China to settle disputes in the South China Sea, very fierce public opposition can be expected from the people and media in Vietnam. And finally, if it makes concessions to China, Vietnam will be shunned by countries like the US and Japan, and its relationship with ASEAN countries will be fractured. Therefore, this second option is unviable.
Third, defensive realism. Vietnam needs to address the "defensive realism" strategy (Blazevic, 2012;Hien, 2015). Defensive realism emphasizes the maximization of states' power and influence in an anarchic system (Hien, 2015, p. 13). The focus of this strategy is the need to strengthen oneself to cope with the impacts of the war. Vietnam therefore, if following this strategy, must invest in building an energetic economic and defense force, converging the internal resources of the entire people; and also in building an international position based on capitalizing on "combining national strength with international strength of the times." This could be a crucial way to protect Vietnam's sovereignty over the South China Sea and its islands in the coming times.
To implement this strategy towards China and the US, Vietnam needs to be pragmatic in economic cooperation (Le Hong, 2013). Dialoguing directly with on a bilateral basis of partnership; balancing softly by strengthening relations with China and the United States and other great powers and participating more effectively in multilateral agreements to pursue specific agendas (Chapman, 2017;Giang, 2022); and finally, increasing its military and defense capabilities in line with other nations to prevent threats.
In defensive realism, the internal force is national synergy, with the total force to ensure the existence and development of the nation-state (Hien, 2015). This includes counting material factors (hardware, such as resources, people, economic, military), spiritual factors (software, such as government quality, education, culture, ideology, religion), and influential power in international relations (foreign policy, positions in international, regional, and global organizations) (Kế, 2007). The defensive realist option allows Vietnam to reap economic benefits and ensure security while remaining steadfast in protecting its interests. Second, it is consistent with Vietnam's multilateral foreign policy, which since the 1990s has emphasized that Vietnam is "ready to be friends" with all countries (N.n.A. Cường & Thành, 2018, p. 362). Third, it allows Vietnam to avoid tumultuous relations with any great powers, which led in the 1970s to decades of conflict.
By choosing this third option, Vietnam will receive the support of the international and regional community, thereby potentially turning the South China Sea into an area of peace, cooperation, and sustainable development. In addition, the building of an accepted institution on the South China Sea dossier among ASEAN countries, and the progress of a Code of Conduct in the South China Sea (COC) are also crucial diplomatic steps that Vietnam needs to work on. These are necessary steps to help Vietnam integrate national interests into common regional interests. This will reduce the risk of having direct confrontation China (Hiếu, 2018). At the same time, it has the support and help of the US, Japan, Australia, India and other countries for the South China Sea issue (Group, International Crisis, 2021;Huong, 2020;Pietrasiak & Pieczara, 2019).

Conclusion
In the long term, China wants to control the South China Sea and surrounding areas in a move to become tremendously influential in the Asia-Pacific region, to attain a position equivalent to and possibly superior to the US. In the medium and short term, traditional military security concerns will continue to dominate China's moves. Therefore, the goal of China is to push the US and allied military presence out of the Asia-Pacific. The perfect outcome for China would be to achieve an equilibrium of military power with the US, or even greater power in strategic seas. And the South China Sea is the main playing field.
The geostrategic location of the South China Sea has made it vital for great powers like the US in the 21st century, which has shifted its policies from neutrality to concern for its "core interests." (Tabbasum & Sobea, 2014) While US statements and actions have become a crucial test against China's intimidation efforts and unreasonable demands, US access to the South China Sea is increasingly threatened as China's muscular power increases. However, if the US maintains a military advantage over China, its goal in this area is achievable. However, the US military advantage in the South China Sea compared to China is limited, so the US would benefit from nonmilitary responses and alliances with Asian countries to prevent China's illegal claims.
The South China Sea issue involves numerous disputed objects directly between countries with sovereignty claims in the South China Sea, including both large and small countries, and disadvantage will be borne by the weak, i.e., relatively vulnerable nations such as Vietnam and other ASEAN nations. Therefore, to protect their sovereignty, these nations must first unite and then employ the collective action of ASEAN nations when dealing with China. Precisely how this might be achieved is a topic of further research.
More generally Vietnam needs an intelligent and flexible foreign policy strategy to maintain independence, sovereignty and territorial unity, and a peaceful and stable environment for developing economies. Good relations with all countries in the world must be fostered, with special attention to harmonious relations with the US and China, so as: "To ensure the highest national interests-based on basic principles of the Charter of the United Nations and international law, equality, cooperation, and mutual benefit. . . Strengthening and deepening bilateral cooperation with partners, especially strategic partners, comprehensive partners, and other important partners, creating an interlacing of benefits and increasing trust." (Vietnam, Communist Party of, 2021) This epitomizes the defensive realism strategy that Vietnam is currently pursuing and while supported by ASEAN, the US and its allies, it is, however, rejected by China.

Acknowledgments
The article was based on official information and authenticated by reputable individuals and organizations worldwide and in Vietnam. Dr. Anne-Marie Hilsdon (Curtin University, Australia) has offered helpful suggestions for revising the text and expanding the scope of the discussion. Anonymous reviewers, you have my gratitude for helping to strengthen this article. BB%83n_%C4%90%C3%B4ng. 9. See more at: https://www.gpo.gov/fdsys/pkg/BILLS-113sres412is/pdf/BILLS-113sres412is.pdf. 10. See more at: https://news.usni.org/2015/10/27/ u-s-destroyer-comes-within-12-nautical-miles-ofchinese-south-china-sea-artificial-island-beijingthreatens-response. 11. In July 2013, during a famous "shirtsleeves" summit with President Obama at the Sunnylands estate in California, President Xi outlined three vital components of such a relationship: "no conflict" and "no confrontation," mutual respect, and winwin cooperation. The two countries agreed to expedite negotiation over a bilateral investment treaty and to begin consultation on confidencebuilding measures between the two militaries.

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