<h3><strong>INTRODUCTION</strong></h3>

<p>The withdrawal of U.S. troops from Afghanistan marks a significant change in U.S. policy in Central Asia. Afghan affairs, which have occupied the core of U.S. Central Asia policy since 2001, will no longer have overriding importance. With the adjustment of U.S. policy in Central Asia, relations between the United States and Central Asian countries, as well as the geopolitical landscape of the Central Asian region, have changed accordingly. These changes have reshaped the environment, which China and the Central Asian countries face in building the New Silk Road Economic Belt together. Taking this background into account, this paper will discuss how these changes will affect the Silk Road Economic Belt project and suggest possible paths for both sides to jointly promote security and development in Central Asia, based on the overview of the changes in the U.S. policy in Central Asia and its characteristics. It needs to be emphasized here that cooperation is not the only way for China and the United States to interact with regard to the Silk Road Economic Belt in Central Asia; it is only one possible option, along with competition and conflict, and it will be more difficult for the two countries to cooperate in Central Asia because of the increasing strategic competition between China and the United States in recent years. However, this paper still indicates that only if China and the United States choose their policies flexibly according to the actual situation, instead of just emphasizing confrontation and conflict, can they really guarantee and promote stability and prosperity in Central Asia and benefit neighboring countries.&nbsp;</p>

<h3><strong>ADJUSTMENT OF THE U.S. CENTRAL ASIA POLICY</strong></h3>

The United States’ Central Asian policy came into a new stage after its military announced the completion of withdrawal from Afghanistan on August 30 ,2021 [1], which reflected certain policy adjustment and continuity.

<em><strong>Afghanistan remains the decisive element</strong></em>

Taking real action with regard to counter-terrorism and reconstruction in Afghanistan has been one of the decisive factors of U.S. Central Asia policy in recent years. The counter-terrorism goal engulfs combatting al-Qaeda, ISIS, and the other radical forces; the reconstruction goal is about rebuilding the Afghan political system, economy, and society. At present, the U.S. counter-terrorism and reconstruction policies in Afghanistan have not changed fundamentally, but the policy content has been adjusted to a certain extent.

After the withdrawal of troops, in the security field with counterterrorism efforts at its core, the U.S. continues to rely on international and regional counterterrorism networks to serve two major security goals in Afghanistan: to deal with the regrouping of terrorists in Afghanistan and potential threat its homeland; and to make the Taliban fulfill their commitments and ensure that al-Qaeda no longer threatens the U.S. and allies’ interests.

With regard to national reconstruction in Afghanistan, the main trend of U.S. policy is the declining and reshaping of its influence. In political affairs, the focus has shifted from proposing different programs to the Afghan government and the Taliban in order to reach balance and achieve political reconciliation, to a “wait-and-see” approach, overseeing Taliban compliance and focusing on promoting the security issues mentioned earlier, although no clear and stable policy has been formed so far. This in turn creates a geopolitical black hole that distracts and puts a burden on neighboring powers. In the economic sphere, the U.S. is trying to build an international system to support Afghanistan. Secretary of State Antony Blinken made it clear that the U.S. continue to support Afghanistan through bilateral and multilateral efforts [2].

<em><strong>G</strong></em><em><strong>eostrategic importance of Central Asia</strong></em>

The geopolitical importance of Central Asia is another key element in determining U.S. policy in this region. Although the U.S. continues to view Central Asia as a geostrategic region important to its national security interests, that has always been a strategic and commercial crossroads of civilizations between Europe and Asia [3], however, what a "geostrategic region" means differs significantly from the popular view about Central Asia’s geopolitical importance. The view of Central Asia as the "heartland" of the world politics has long been popular. A historical tracing and realistic comparison can reveal that it no longer corresponds to nowadays reality. This kind of view is very close to the Heartland Theory formulated by Halford Mackinder in the early 20th century [Mackinder, 1904: 421-437]. Mackinder based his famous and far-reaching assertion on the changing regional patterns brought about by land mobility in Eurasia after the Industrial Revolution, which was relevant at the time. With the advancement of new technological revolutions, transportation and communication technologies have developed by leaps and bounds in the last hundred years, and the geopolitical meaning of land mobility has changed dramatically compared to the first part of the 20th century, and its influence on the geopolitics of Central Asia has been significantly reduced. As a result, the metaphysical application of the Heartland Theory is no longer a reasonable way for describing the geopolitical reality in Central Asia, nor is it the solid basis for understanding the power games among United States and other countries in Central Asia. This kind of change is also reflected in the U.S. Central Asia policy in the post-Cold War era. The United States has not had a consistent Central Asian strategy over the past three decades. Although the term "Central Asia Strategy" has been used several times, such as in 2015 and 2020, it has mainly defined how the U.S. uses Central Asia to serve its policy in the region. For example, after the September, 11 attacks, counterterrorism and reconstruction in Afghanistan became the core of the U.S. Central Asia policy; before and after that, it served the goals of the U.S. policy toward Russia, China, and other countries.

In other words, although the U.S. Central Asia policy will inevitably have geopolitical implications, Central Asia has not been the core area of U.S. geopolitical strategy in the post-Cold War era. This policy has been mainly influenced by the U.S. policies toward neighboring countries and regions, and has been characterized by strong incoherence and uncertainty during the past 30 years. After the U.S. withdrawal from Afghanistan, the Biden administration did not make Central Asia a foreign policy priority [Krol, Kassenova], some commentators point out that, since U.S. abandoned Afghanistan, it has very few geopolitical or strategic interests in Central Asia except to try to keep the Chinese and the Russians out [4].

<em><strong>Emphasizing the Subjectivity of Central Asia</strong></em>

The February 2019 agreement between the United States and the Taliban not only indicated a new phase of U.S. policy in Afghanistan, but also implies a corresponding change in U.S. policy in Central Asia. In February 2020, the United States released the Central Asia Strategy 2019-2025: Advancing Stability and Prosperity, which clarifies the main elements of the U.S. policy towards that region. Although this strategy still includes dealing with Afghanistan as one of the key elements, it also the importance of making the region more independent, stating that the United States will strengthen the resilience of Central Asian states to address short- and long-term challenges and enhance the stability, independence, and integrity of the Central Asian region through continued engagement in economic, energy, security, democracy, and governance issues in this region [5, p. 3]. The U.S. Central Asia policy after Biden came into power continues to follow with this primary direction, attempting to strengthen the agency of the U.S. Central Asia policy.

Firstly, highlighting the role of regional platforms, it has constructed the U.S.-Central Asia mechanism with C5+1 as the core. Since its establishment in 2015, the C5+1 mechanism has become one of the main ways for the U.S. to oversee its Central Asia policy. This mechanism not only plays an important role in coordinating Central Asian countries’ policies with regard to Afghanistan, but also provides support for the U.S. to build a more independent and unified Central Asia regional policy through five types of projects¹. Secondly, factors such as human rights, religion, and values become more prominent. An important goal of the U.S. policy in Central Asia is to promote the 5 countries’ political and economic transition. However, the U.S. policy of exporting democracy to Central Asia has been disturbed by the Afghan war, because ensuring Central Asian countries’ cooperation with the U.S. on the war on terror in Afghanistan has been a central goal of the U.S. Central Asia policy for the past two decades. The end of the war in Afghanistan and withdrawal of the U.S. troops have reduced its dependence on Central Asian countries, and therefore human rights, religion and other democratic issues became more prominent in U.S. policy in Central Asia. Finally, support and strengthening of sovereignty and independence of the Central Asian states, individually and as a region is one of the primary objectives of U.S. Central Asia policy [5, p. 3]. Its strategic meaning is to reduce the dependence of Central Asian countries on China, Russia, and other actors.

<h3><strong>HOW THE U.S. POLICY INFLUENCES THE SILK ROAD ECONOMIC BELT</strong></h3>

The New Silk Road Economic Belt (SREB) is one of the main components of the Belt & Road Initiative (BRI). The development of the SREB in Central Asia requires support of the countries in the region, as well as it needs to overcome the challenges from the outside countries. Since the United States is one of the countries with most significant influence on Central Asian affairs, the U.S. Central Asia policy and its adjustment become an important factor that China must face when promoting the construction of the SREB with Central Asian countries. Generally speaking, the U.S. Central Asia policy of promoting regional integration in South and Central Asia, attracting the participation of neighboring powers, and reshaping rules and institutions is changing the regional environment.

<em><strong>P</strong></em><em><strong>romoting regional integration in South-Central Asia</strong></em>

After the U.S. had withdrawn its troops from Afghanistan, its Central Asian policy continued to take the promotion of regional integration in Central and South Asia as one of its main purposes, which is consistent with the U.S. strategic pursuit of ensuring that the Central Asian region is not dominated by neighboring powers. After the collapse of the Soviet Union, the U.S. used to support the Central Asian states’ participation in international affairs as independent states and refused to accept this region as part of Russia's sphere of influence. According to the Silk Road Strategy Act and the Freedom Support Act, which are the key legal basis for U.S. policy in Central Asia, helping Central Asian countries consolidate and maintain their sovereignty and independence is one of the main policy goals. While improving cooperation with Central Asian states, U.S. is also paying close attention to the growth of other powers' influence in Central Asia, especially China. As a result, the U.S. strategy in Central Asia gained new content, such as strengthening ties between Central Asia and South Asia, forming a new Central Asia-Afghanistan-South Asia geopolitical block, thus reducing Central Asia's dependence on the North (Russia) and the East (China). The famous Greater Central Asia project, the foundation of the Bureau of South and Central Asian Affairs in the State Department, the New Silk Road Initiative and the AfPak Strategy are all based on the similar principle of the regional integration. The US is committed to expanding the internal ties of South and Central Asia in the areas of energy, trade, and investment to enhance its unified geopolitical attributes. For the SREB, the U.S. promotion of regional integration in South and Central Asia has dual impact. The positive side is that the development of a unified market and increased resource integration in South-Central Asia could theoretically enrich the basis for the implementation of the SERB projects; the negative side is that the integration process in South-Central Asia is likely to set up new thresholds that will prevent Central Asian countries from joint cooperation with China. Given that the U.S.-driven integration in South-Central Asia is intended to prevent and contain the growth of China's influence, its impact on the Silk Road Economic Belt is mainly negative.

<em><strong>Manipulat</strong></em><em><strong>ing neighboring powers to participate</strong></em>

The U.S. has adopted a flexible strategy to deal with the issue of great power games in Central Asia. In the past two years, under the premise of solving Afghanistan issues, the U.S. has invited China, India and other neighboring powers to participate in regional affairs around the topic of Afghanistan reconstruction and stability. From the U.S. perspective, China's participation will help share the economic cost of Afghanistan's reconstruction. The policy is not contradictory to the U.S. strategic orientation of integrating Central Asia to the south. The former solves the problem of insufficient resource input in the process of Afghanistan reconstruction, while the latter determines the direction of strategic development of Afghanistan. Moreover, if the United States can play a guiding role in China's involvement in Afghanistan, it can create favorable conditions for it to integrate China's Afghanistan policy into its own orbit as much as possible and better control the changes in China's influence on Afghanistan. Encouraging India's participation in Afghanistan and Central Asia has deeper geopolitical implications than just supporting the reconstruction of Afghanistan. On the one hand, India's active participation in Afghanistan and Central Asia is a key part of shaping the unity of the South-Central Asian region; on the other hand, India's rising status can also help balance the influence of China and Russia in the South-Central Asian region and form a regional balance of power in favor of the United States. The implications of manipulating neighboring powers to participate in Central Asian affairs are similarly dual in nature. On the positive side, China's deep involvement in the reconstruction of Afghanistan can expand the ties between China and Afghanistan and the Central Asian countries, and create conditions for the development of the SERB in the region; on the negative side, if India or the U.S. put forward competing proposals for regional cooperation due to geopolitical competition, it will most likely increase the pressure and cost of the SERB projects and hinder its development in Central Asia.

<em><strong>Focusing on developing regional rules</strong></em>

Shaping rules and institutions is a basic strategy pursued by the United States in Central Asia, which mainly includes: promoting values such as democracy, human rights and religious freedom while emphasizing the imperfection of its competitors; providing economic assistance, technical training and experience dissemination to serve the economic and market system; providing equipment and security assistance to support the security system; and establishing regional cooperation mechanisms aimed at forming a regional system conducive to strategic balance. Shaping rules and institutions with its own standards can influence the development of the SREB at a deeper level than cooperation or competition in specific projects. Since the BRI focuses on economic cooperation and common development, the institutional rules shaped by the U.S. in the economic sphere can more directly influence the progress of the SREB. In the economic field, the U.S. emphasizes its own advantages in terms of norms and standards [5, p. 3], and uses relevant economic and technical assistance, training, and educational exchanges to persuade and guide Central Asian enterprises, social organizations, and even individual citizens to accept the U.S.-style corporate systems, economic norms, and codes of conduct, while externally using existing international standards, international rules, and its own assumptions to interfere with the SERB processes [Ma, J. 2015: 123]. If economic norms and business rules in Central Asia were to be accepted or approximated to U.S. standards, this would create an economic environment and opportunities conducive to the success of U.S. companies, and establish the U.S. as a rule-maker, thus reducing the direct impact of the SREB on the U.S. influence in Central Asia. Indeed, the emphasis on regional rules and institutional shaping is also consistent with the logic of U.S. responses to pressure. Most of the US economic initiatives in Central Asia are constrained by funding and competition within the bureaucracies, and it is difficult to launch large projects and fulfill the economic commitments, which would disappoint its Central Asia partners. Therefore, it has become a rational choice for the United States to build up its strengths and avoid its weaknesses by shaping the institutional environment in its favor. Compared with China's economic policy, which focuses on capital and technology investment, the U.S. has adopted rule-introducing as the core of its policies in Central Asia, which promote U.S. standards, business laws and enterprise operation rules in Central Asia, thereby enhancing U.S. soft power in this region. This will fundamentally affect the environment where the SREB functions.

In summary, U.S. policy adjustments in Central Asia continue to shape the environment facing the SREB. Although the U.S. declared early on that its Central Asia policy would use U.S. leadership to promote connectivity between Europe and Asia, the East with the West [6], the geopolitical consideration like ensuring that no single power controls this geopolitical space alone, continues to influence its thinking about the SREB. As the U.S. attitudes and policies are still in change, its impact on SREB will become clearer and more specific.

<h3><strong>CHINA'S POLICY OPTIONS AND RESPONSES</strong></h3>

The U.S. policy in Central Asia is an important factor in shaping the environment which SREB is facing. China is very concerned about the influence of the United States in the process of promoting the construction of the SREB in Central Asia. For China, upholding the openness and cooperation, choosing a flexible policy to respond to the opportunities and challenges brought by the policy changes of U.S. is the primary principle to promote the progress of the SREB in Central Asia. In general, China should pay attention to the negative influence of the U.S. Central Asia policy, but should also take the cautious attempts to find opportunities to reduce barriers to the SREB development in Central Asia. Although the change of the U.S. attitude toward the SREB does not mean that it will participate, it offers more possibilities for Chinese companies. Specifically, Chinese companies could follow the market rules when they enter into Central Asia, and rely on bilateral, multilateral, regional or sub-regional frameworks to get a relatively friendly business environment, so as to promote the development of the SREB in this region.

<em><strong>Improving the coordination efficacy of the bilateral approach</strong></em>

The bilateral approach is currently the main pillar of China's joint efforts with Central Asian countries to build the SREB. In fact, considering the impact of U.S. policy on the business environment in Central Asia, China's bilateral coordination around the SREB should at least include China and the five Central Asian countries, China and Russia, and China and the United States. The reason why bilateral coordination can be the basis is related to reality that both the low level of economic integration in the Central Asian region and the distinctive features of economic cooperation between China and the Central Asian countries; more importantly, China's relations with the Central Asian countries have long been based on bilateral cooperation, with multilateral channels usually functioning as an important complement. The bilateral approaches between China and the five Central Asian countries provide the most direct channel for their coordination related to the SREB, helping China and the Central Asian countries to clarify their intentions, areas and ways of strengthening cooperation within the framework of the SREB. The bilateral coordination between Russia and China stems mainly from Russia's great influence on Central Asian affairs. The conjunction agreement of the BRI and Eurasia Economic Union provides an important guarantee for the progress of the SREB in Central Asia. At the same time, effective Sino-Russian coordination can also constrain unilateral behavior of the United States in Central Asia. China-US coordination is based on the U.S. influence in Central Asia. Although bilateral communications between U.S. and China did not lead to a fruitful result, China insists on developing SREB in an open and cooperative manner, which is still the important support for both sides to increase trust in Central Asia, which can create better conditions for the development of the SREB in this region.

<em><strong>Make full use of the multilateral platforms</strong></em>

International and regional organizations are important multilateral platforms for China and Central Asian countries to build the SREB together. Since their independence, the five Central Asian countries have joined numerous political, economic, and security organizations, both international and regional, such as United Nations, the World Bank, the International Monetary Fund, the Eurasian Economic Union, the Shanghai Cooperation Organization. The role of international and regional organizations in the building of the SREB mainly includes two aspects. First, to shape and enhance the international image and influence of the SREB. At present, the UN Security Council and the UN General Assembly have successively incorporated the BRI as an important means to solve regional stability, development and global issues into relevant resolutions². The World Bank officials have also expressed their intention to explore opportunities for cooperation with the BRI [7]. The endorsement or support of the BRI by the United Nations, the World Bank, and other international organizations with great influence can produce a good demonstration effect in the international community and enhance the attractiveness of the SREB, which is also conducive to balancing and reducing the impact of U.S. policies on the Central Asian countries. It is also conducive to certain balancing and reducing strategic doubts brought by the U.S. policy in Central Asia, thus improving the environment around the SREB in Central Asia. First, it provides and supplements the mechanisms for China to dovetail with Central Asian countries on the SREB projects. The advantages of international organizations in terms of communication efficiency and transaction costs allow China and Central Asian countries to use these platforms to coordinate objectives, communicate policies, and reduce the concerns of Central Asian countries arising from asymmetric interdependence with China, and promote the development of regional projects. Of course, not all international organizations in which Central Asian countries participate can serve as a platform for Silk Road development, it depends much on China's coordination with the countries concerned and the nature of a given international organization.

<em><strong>Building the mechanism of the Silk Road</strong></em>

The Asian Infrastructure Investment Bank (AIIB) and the Silk Road Fund (SRF) are the key for China’s promoting of the BRI. They are the BRI core supporting institutions that China has advocated or established separately to implement Chinese proposals and solutions, safeguard and protect Chinese interests in the process of developing the BRI. However, these institutions are newly established, and their growth and development cannot be achieved without learning from the experience of similar institutions. The World Bank, the Asian Development Bank and the European Bank for Reconstruction and Development, for example, have accumulated a lot of experience and best practices during their lifetime, and have established a relatively stable system of operation, which can be used by the AIIB as a reference point as well as for implementing projects in cooperation with these institutions. In fact, in addition to studying and learning from their experience, AIIB is already looking for cooperation with the ADB, the World Bank, the European Bank for Reconstruction and Development, etc., and has initiated several joint projects. In 2015, the ADB President said that under conditions that meet certain criteria, ADB hopes to start cooperation with AIIB [8]. AIIB has planned to co-finance eighteen projects initiated by the World Bank and eight ADB projects [Orr, 2016: 39-43]. In Central Asia, AIIB has implemented projects in partnership with the EBRD and the WB [9]. The WB, the ADB and the EBRD are typical representatives of the Western development model, and the AIIB's cooperation with them provides important evidence that the Silk Road+ mechanism model for the BRI development is conducive to weakening the pressure from the United States and further expanding the development space of the SREB in Central Asia. At a more macro level, the BRI and its supporting institutions, if properly applied, will enable China to play an increasingly important cooperative and constructive role in the international system [10].

Of course, China's policy options based on changes of the U.S. Central Asia policy and their strategic implications will include not only the three areas discussed here. China's response to the implications of the U.S. Central Asia policy at the level of bilateral cooperation, international organizations, and the construction of the BRI mechanism does not suggest that conflict or cooperation will be the only features that dominate U.S.-China interaction around the development of the SREB in Central Asia. As mentioned above, great influence the United States has in Central Asian affairs determines that China needs to expand the scope and flexibility of its policy toward the United States in Central Asia, and the basic direction of China's strategic response to the U.S. influence is to strengthen the bilateral foundation, solidify the international platform, and develop the "Silk Road+" mechanism.

<h3><strong>CONCLUSION</strong></h3>

In conclusion, it needs to be noted that the withdrawal of the U.S. troops from Afghanistan marks a new phase of U.S. Central Asia policy. The U.S. Central Asia policy in the past two years or so has been characterized by a shift from a security-led to a diversified and balanced approach that include economics, politics and security, promoting regional integration in South and Central Asia, guiding the participation of neighboring powers, focusing on rules and institutional shaping at the strategic level to influence the environment facing the SREB in Central Asia. China cannot escape the pressure of U.S. policy in shaping the regional environment, and needs to reasonably apply bilateral, multilateral and regional mechanisms and actively build a "Silk Road+" mechanism based on China's core supporting institutions to improve the flexibility of its policies in Central Asia, in order to achieve better performance when dealing with numerous challenges in Central Asia.