Geopolitical Dynamics of the Persian Gulf and Central Asia in the US Global Policy

The demise of the Soviet Union and the end of the bipolar system affected the geopolitics of the glob. One of the main features of the new world system is the importance of the world economy; accordingly, any power that dominates the Persian Gulf, with its enormous energy resources, would dominate the world. Yet, Central Asia, with its energy resources and strategic location, has attracted the powers attention. Under the new circumstances, the United States has tried to play an influential role in both regions. Here the main question is: which region is more important in US foreign policy, the Persian Gulf, or Central Asia? The paper concludes although Central Asia has a special role in US global policy, particularly after the 9/11 events, the Persian Gulf, for its greater amount of energy and crucial geopolitical position, as a new “heartland” or “center of the center” contains long-identified vital US national interests and security more than any other region.


Introduction
The breakup of the Soviet Union and the disappearance of the bipolar system in the international arena influenced the playing field and the international actors. Under the new circumstances, with no other effective dominance power, the United States tried to play an influential role in the glob. Accordingly, land-based powers, in the following manner: 'Who rules East Europe commands the Heartland; Who rules the heartland commands the World-Island; and who rules the World-Island commands the world' (Mackinder, 1904). In 1942, Nicholas Spykman (1893-1943 proposed a geopolitical model contrary to Mackinder's 'Heartland' theory. He argued that 'Eurasia's Rimland,' the coastal areas or buffer zone, not the 'Heartland,' was the key to controlling the 'World Island.' (Spykman, 1942) Spykman, as a realist, viewed international politics as a struggle for power, in which Anglo-American national security necessitated control of the 'Rimland' as a means to block the expansion of the 'World Island.' (Spykman, 1944)

Map 1: Mackinder's Original Model of the World
The post-Second World War geopolitical outlook, however, indicated a changed approach by entwining geography closely with ideology from the very beginning of the US-USSR rivalry in 1946. The Heartland-Rimland thesis became the conceptual basis for post-1946 US policy visà-vis the Soviet Union, with the United States seeking to establish hegemony over the 'Rimland.' According to one historian of the Cold War, J.L. Gaddis, in the late 1940s 'there developed a line of reasoning reminiscent of Sir Halford Mackinder's geopolitics, with its assumption that none of the world's 'Rimlands' could be secure if the Eurasian 'Heartland' was under the domination of a single hostile power.' (Gaddis, 1998) The basic premise of the US strategy of 'Containment' was aimed at excluding the Soviet Union from the 'Rimland' and containing it within the 'Heartland.' Still, the Soviet Union countered by establishing its hegemony in Eastern Europe, Eurasia, Northern Asia, and part of Southwest Asia. 2 Geopolitics, as a grand strategy was one of the significant intellectual bases for the US containment policy, based on Mackinder's vision (Fettweis, 2000;Dalby, 1990). However, in recent years the importance of these factors has diminished.
Mackinder's theory, indeed, is one of the influential theories for studying the geopolitical and geostrategic situation of Eurasia. In this theory, historical and geographical features are combined and provide a special index for the division of important regions of the world. The theory that antitheses to Mahan's theory have been completed to date with the opinions of critics such as Spykman, Cohen, and Mahan. Contrary to Mackinder's views, Mahan's theory emphasized the importance of naval power and the control of maritime communications as the most effective way to exercise control and power in the world.
Nicholas Spykman also believes that the various processes of cooperation, study, and conflict of countries in the international arena force them to become strong or supported by a great power to maintain and guarantee their survival. According to him, expansionism begins when there is a weak link in the international power system (Seifzadeh, 1997). Inspired by Mackinder's theory, he proposed the Rimland theory and suggested that the Rimland should be protected to preserve the heartland. The difference in their views is only in the relative importance of Rimland vs. Heartland Eurasia (see map 2).
2 In the 1940s, N.J. Spykman warned that US leaders should form a containment policy to prevent the 'rimland' from falling under Soviet control. In 1992, research by Nijman revealed that the 20 countries in which the USA and USSR had the most serious conflict largely formed a crescent around the Soviet borders, similar to Spykman's 'Rimland'. Spykman, America's Strategy in World Politics: The United States and the Balance of Power, pp. 23-42, and Spykman N. The Geography of Peace, Harcourt, Brace, 1944, pp. 40-44.

Map 2: Mackinder's Heartland and Spykman's Rimalnd (Rajasimman, 2019)
The importance of the theories of geopoliticians such as Mackinder, Spykman, Maing, Hoffro Mahan in the political and military developments of the Twentieth Century, and the formation of the First and Second World Wars over the seizure of power and wealth led to the two crucial issues geopolitics and geostrategy.
Military strategies in the Twentieth Century had played a key role in dominating the territory of nations, while in the 21st Century, this is not the case as in the past. In this century, any state that can dominate the resources and energy pipelines will have a global power (Yazdani, 2006). Therefore, in the new world system, the regions with a geoeconomic position have a better situation. Accordingly, the Middle East and its subsystem, the Persian Gulf region, located in its center and has enormous energy reserves with a geostrategic, geoeconomic, and geopolitical position, are very significant in the new international system. The Persian Gulf, which in old geopolitical theories was considered as a rimland, has now become the "heartland" or "center of the center" in new theories.
For the United States, according to Brzezinski, Eurasian geostrategy involves the purposeful management of geostrategically dynamic states. He has argued that the United States 'is now Eurasia's arbiter, with no major Eurasian issue soluble without America's participation or contrary to America's interests' (Brzezinski, 1997). Therefore, this is essential to sustain the unique position of the United States as the world's sole superpower (Brzezinski, 1997). Moreover, US involvement in this pivotal region enables Washington to integrate it into its global strategy, given careful handling of the geopolitically catalytic states, in keeping with the twin interests of the US in the short-term preservation of its unique global power and long-run transformation of it into increasingly institutionalized global cooperation. It can be argued that the World Island is still the central focus of US foreign policy and that it is Central Asia's proximity to Russia, China, Iran, and Persian Gulf/Indian Ocean that has made it increasingly of interest to the United States. It is believed that 'this region should matter to the Unites States because it matters considerably to every other major Eurasian power whose global and regional interests affect US interests. ' (Starr et al. 2001).

The Importance of Central Asia
The region of Central Asia, which stretches from the Caspian Sea and the Caucasus in the west to China, has had a special place in the policymaking of the regional and global powers during the history (see map 3). This region, according to Mackinder's geopolitical theory, is the Heartland of world politics. The chessboard of imperial rivalry existed between British and Russian empires caused by their expansionist polices. So in the 19th century, there had been a competition, called the great game, between British and Tasrist Russia for influence over Central Asia owing to its location at the crossroads of different civilizations and the old silk route. The significance of this imperial rivalry was attributed to Mackinder's geopolitical analysis and named it as the heartland. Hence, whoso ever wanted to be an influential power player in political dominance with economic fruition had to turn towards Mackinder onception of Heartland (Fatima, 2012).

Map 3: Central Asia
This region has received more attention since the early 1990s and the formation of emerging countries from the former Soviet republics. The region's energy resources are significant, and its location is strategically important. Located at the center of Eurasia on the intersection of critical transport routes, Central Asia represents a strategic component of the Eurasian continent. The republics of Central Asia serve as a bridge between East and West (Rumer, 1996). They are flanked to the east by a rising great power (China); to the North by their former hegemon (Russia); to the south by a country collapsed in violent chaos (Afghanistan), and an Islamic republic (Iran), and a brittle secular state in search of a greater regional role (Turkey). Along with these, great global powers such as America seek to influence and dominance (Azarkan, 2010).

In Regards to the Great Powers' Attention to this Region, Several issues can be Mentioned
The main reason for paying attention to Central Asia is the rich energy resources available in the region (see table 1). Regarding the geoeconomic importance of the region, it can be said that Kazakhstan is a large country with a not big number population, full of oil and gas resources, gold, uranium, copper, and other mines. Azerbaijan and Turkmenistan have huge oil and gas reserves. Uzbekistan with a considerable population and Kyrgyzstan has cotton and gold, Kyrgyzstan has a small amount of gold but huge reserves of water, and finally, Tajikistan has gold resources and water (Beddoes, 1998). Although comparing with the Persian Gulf, Central Asia does not play a significant role in meeting the needs of the industrial world in the current situation, but due to the pristine and untapped resources in this region in the coming decades, the role of this region in the energy supply of industrialized countries will increase. B-Another reason is the significant geopolitical position in Central Asia. The region borders Russia, on the one hand, China, on the other, and countries like Iran. Accordingly, great powers such as the United States view the region as a control belt for their rivals and enemies in the Middle East and North and East of Asia. Also, the Central Asian region is considered as a transit route for drugs to Europe and the United States; this issue has also increased sensitivities to the security of this region.
C-Regarding the geostrategic importance of the region, one can mention that on the one hand, the region is the junction between Europe and Asia and between the civilizations of Islam and Christianity. Russia is in the south, followed by Turkey (a secular state with a view to regional domination), Iran (an Islamic state seeking regional influence), and Afghanistan (a country with war and instability), and finally China, a global power. Outside this region, the United States of America wants to influence and dominate it, while the energy resources of the Caspian Sea must be added to this image (Haj Yousefi, 2005).
The D-Another reason is that the great powers' special attention to Central Asia is a good ground for the activities of fundamentalist Islamic groups in some countries in the region. Basically, after the Middle East, Central Asia is the second center for fundamentalist Islamic groups' activities. This has also raised sensitivities in the region; the activities of these groups are closely monitored by major powers such as the United States.
Given the importance of the Central Asian and Caucasus region and the geopolitical vacuum resulting from the collapse of the Soviet Union and Russia's initial retreat into the borders of the Russian Federation, these conditions led to the presence and influence of regional and global actors in the region, led to a "new great game" in the area. The term "The Great Game" was used to describe the rivalry between Russia and Britain for control of Central Asia in the 19th century (Blank, 2012). This new great game is mainly about economic interests (especially regional energy resources) and political (influence and domination of the region). Indeed, the new great game has been taking place mainly between regional actors (Russia, China, Iran, and Turkey) and trans-regional actors (the United States and, to some extend, Europe) and some other countries and multinational corporations in the region.

The Significance of Central Asia in US foreign Policy
With the collapse of the Soviet Union and the end of the bipolar system, the US role, as the only superpower in the international system, increased. In the post-Soviet era, the United States found itself in a new situation and shifted its traditional focus from Europe to Asia. In this regard, US policy at the beginning of the independence of Central Asia and the Caucasus was more influenced by its foreign policy in the Middle East. (Maleki, 1998). The main objectives of Washington's foreign policy in the region were to contain Russia on the one hand and to control Iran on the other. The challenges that the United States faced were: Russia's re-attention to the region as private life and its close alien; also, the countries in the region were traditionally dependent on Russia since late 1991, Washington has been trying to connect the newly independent countries to the Western camp.
The most important tool of US foreign policy in the region was to take advantage of its allies, Turkey and Israel. It can be said that Turkey and Israel acted as US agents in the region in the 1990s (Yazdani, 2020). Azerbaijan was the first country to be attracted to the US coalition in the region. The US tried to contain Iran by creating regional coalitions and even direct intervention to prevent Tehran's politicoeconomic opportunities in Central Asia. The 9/11 terrorist attacks highlighted US national interests in Central Asia and left Washington with deep-seated problems in Central Asia. 1. The United States seeks. To contain Russian influence in the region. The United States seeks to limit Russia's influence by strengthening and supporting the independence of the Central Asian republics. It has always sought to fill the geopolitical vacuum surrounding the Russian Federation. Washington also seeks to reduce Russian interference by resolving regional crises and financial and economic assistance to these republics (see the below tables 2, 3, and 4). (Hashemi, 2003).   2. To contain Chinese involvement and influence in Central Asia.

3.
To provide opportunities to the Central Asian states to access world markets outside the region (Blank, 2008). 4. To control the oil and gas transportation routes to create an anti-monopoly over the region (Kolaei, 1995).

5.
To promote western democracy in Central Asia (Boonstra, 2012). However, nothing has been done with democracy in these republics yet. For Washington, Turkey has been a desirable secular model for the newly independent countries of the region. Because Turkey is a Western-oriented country and a member of NATO. Regarding the Turkish model, a few points are important for US foreign policy: • Turkey is in line with the United States in terms of Western values and system of government; • The predominant language of these republics with Turkey can weaken the culture of Islamic fundamentalism in the region (especially in the Republic of Azerbaijan); • Turkey is a military ally of the West and the United States, and the countries of the region can count on the military role of this country (Kolaei, 1995;Yazdani, 2020) 6. To eliminate terrorism and Islamic extremism from the region. Washington has become concerned about the growth of Islamism in Central Asia. In 1992, for the first time, the United States seriously stated that one of its goals in the region was to prevent the growth of Islamism in the newly independent republics. Senior US officials warned the leaders of the region about the influence of Islamism. The reflection of this fear was well illustrated in Brzezinski's words: "The dangerous vortex that might arise from creating a political, geographical vacuum for the United States and Russia is Islamism. The growing Islamic awakening is not just a collision dealing with Russia's interests; it is a threat to America's superior sovereignty in the region and the world as well" (Hashemi, 2003 (Bagbaşlıoglu, 2014) 9. Controlling and isolating Iran: Since the Islamic revolution in 1979, and the fall of the Pahlavi regime in Iran, the Islamic Republic of Iran has become the biggest opponent of the United States in the region. Washington first applied the policy of sanctions against Iran and then the policy of controlling and finally placing Iran in the list of the axis of evil (plus Iraq and North Korea) 3 s power objectives such as weakening Iran's power and preventing it from emerging as a regional power and preventing its internal and external growth have been major Washington's goals. Because Iran, in addition to the geographical exception and the ancient historicalcultural ties with Central Asia, was considered as the closest consumer market and also an appropriate center to meet the economic needs of the region, and a proper route for exporting the region's oil and gas to the global markets as well. (Pavliuk, 2000). Therefore, preventing Iran from cooperating with the republics and its influence in the region has been another US goal.

The Importance of the Persian Gulf and US Goals in the Region
The Persian Gulf, as the Middle East sub-region, is amongst the most vital regions of the world and major centers of world affairs, an economically, geopolitically, politically, strategically, and culturally sensitive area (see map 4) (Stivachtis, 2018). The region location has given it significant geopolitics, economic, and strategic position. Indeed, control of the Persian Gulf will be a key factor in the global balance of power between the West and East great powers (Barzegar, 2010). In addition to its exceptional position and enormous oil and gas reserves, other factors such as the geopolitics of media, terrorism, nuclear rivalry, advanced conventional weapons accumulation, and establishment of military bases in the Arab states of the Persian Gulf are contributing to the geopolitics of this significant area (Farajirad, 2019). The Persian Gulf region is an important -cross road of the world, commanding the strategic approaches to Asia, Africa, and Europe. It has been coveted during history by all major powers of the world, including Britain, and the former Soviet Union, for its geopolitical importance and significance for the global trade.

Map 4: The Persian Gulf (Drishti, 2020)
The Persian Gulf is one of the most significant regions that has always been of interest to the United States and has been of vital importance to Washington. No other region of the world has been as much strategically significant to the US as the Persian Gulf. The US President, Eisenhower, described it in 1951 no more strategically important area in the world. Later, President Carter said that as oil imports to the United States were rapidly growing; the Persian Gulf had become vitally important for the country. In Reagan's geostrategy, the area was given "priority" (Cambell, 1981;Alam, 1993). The importance of this region has not only diminished since the breakup of the Soviet Union but has also increased due to special circumstances. Geopolitics has a special place in shaping the strategy of the great powers in this region. Another issue is the direct or indirect dependence of the industrial countries on this region (for the region energy, see table 5). This dependence has led the great powers, particularly America, to have a special view of this region and to consider it as their backyard. To maintain its dominance over the international political economy and international relations, the United States sought to develop active strategies, especially after the September 11 events in the Persian Gulf. (Asadian, 2002). * Iran oil production is reduced due to US sanctions.
In the context of "the new world order" notion and other strategies, the Middle East remains as the world's oil depot for the United States. After 9/11, Washington raised the issue of "regime change" in the region in the framework of political reform and so-called democracy. The "Greater Middle East" plan that paved the way for its implementation after these events were the most important goal. To this, Washington, in particular, neoconservatives, the Bush administration, tried to achieve the following goals in the framework of "the greater Middle East" plan: Controlling over the region energy resources, the gradual geopolitical shift in the Middle East, promoting political reform, strengthening Israel's regional position, and containment of Islamic fundamentalism (Al-Qahtani, 2019).
Two-thirds of the world's oil reserves (see table  6) and one-third of the world's gas reserves are in the Persian Gulf, and despite rich exploration in other parts of the world (such as the Caspian basin) for many years, no other region can replace the Persian Gulf. The oil of the region, indeed, is the most important vehicle for the West and East industry and development (Asadian, 2002). The US economy's dependence on oil has put the Persian Gulf in the center of US strategy; in other words, the "oil tap" is in the Persian Gulf. Thus, any instability and crisis could threaten US interests and energy security in this region. Regarding the US desire for continuation presence in the Persian Gulf, the report of the then US Secretary of State George Schultz mentioned three issues: 1. Cutting off the flow of oil by controlling this energy source by an unfriendly power can have devastating effects on global trade and the US economy. 2. If, as a result of Iran's expansionism, the governments of friendly countries are overthrown, or the anti-American forces in the region are strengthened, American interests would be greatly endangered.

As a part of the strategic passage in the Middle
East, this region can be dominated by a hostile power towards the United States and its allies (Ezzati, 2002). The Persian Gulf is the only region that can be the last source of energy in terms of surplus production capacity and is of strategic importance in this regard. Therefore, US troops in the region can safeguard its long-term economic goals and energy security. (Ezzati, 2002). Indeed, the geopolitical, geostrategic, and geoeconomic importance of the Persian Gulf has made this region a place for maneuvering of great powers, including the United States, because in addition to its energy and geopolitical position, with its over 180 million population(see table 7), it is a good market for the great powers production including military weapons (Rashed, 2019). That is why influence in the Persian Gulf region and establishing military bases and maintaining security and stability are part of Washington's global grand strategy. By the way, one can assume that oil as a strategic commodity has a close relationship with US hegemony. To this, Bush, the first, once stated: "My administration, like other American presidents from Roosevelt to Reagan, is committed to the security and stability of the Persian Gulf" (Brands, 2004). Generally, the Persian Gulf is a Critical Region for the United States for Several Reasons 1. The most important U.S. interest is ensuring the free flow of oil from the region to the world markets. Since the United States assumed primary responsibility for protecting Western interests in the Persian Gulf in the 1950s, its essential objective has been to ensure the free flow of oil at reasonable prices from this region to fuel the economies of Europe, Japan, and the United States (Indyk, 2004). States in the Persian Gulf will remain leading oil exporters in the next decade, although the degree of their dominance will depend heavily on the price of oil. Needles to mention that the Persian Gulf also has tremendous natural gas reserves. Energy, indeed, historically is the number-one rationale for US concerns about regional security. 2. The United States also seeks to ensure the security of its friendly regimes in the Persian Gulf. In the last decade, the United States has developed strong and close relations to Saudi Arabia, Kuwait, the UAE, Bahrain, Qatar, and Oman (Byman, and Wise, 2002). 3. The United States seeks to prevent any single power from establishing hegemony over the Persian Gulf. U.S. interests in the Persian Gulf are so important that Washington must ensure they are not vulnerable to pressure or blackmail.
In this regard, the United States is highly concern about two issues: other powers influence in the region would open up opportunities for regional states to balance American influence by appealing to those powers such as European countries, Russia, or China. US' second concern is that some of these great powers could furnish the Persian Gulf states with highly sophisticated weaponry (Sokolsky and Rumer, 2003).
The events of September 11, however, starkly emphasized that any strategy aimed at fighting against terrorism with global reach must focus heavily on the Persian Gulf region, where so many of the September 11 terrorists originated (i.e., Saudi Arabia) (Mcmillan, 2003) 4. To contain Iran and to prevent it from becoming a regional power (Niehaus, 2019). 5. Bilateral defense arrangements with Arab states of the Persian Gulf, in order not only to grant the US access to their bases and military but also to establish and station its military bases and equipment in the region (Indyk, 2004).

Comparing the Importance of the Persian Gulf and Central Asia to the United States
The effect of geographical factors on power relations in international politics is the main geopolitical agenda. The heart of the earth (Heartland) and the Rimland are complex. The Mackinder Heartland and the Spykman Rimland are good examples for classification of the world.
Mackinder considered the landlocked region of Eurasia to be the heart of the earth (Heartland) and claimed that Heartland is the key to global control. He believed that world history marked a constant conflict between land and sea powers (Mackinder, 1904). Mackinder's arguments referred to the geopolitical rivalry between Russia and Britain and later the United States.
After the demise of the Soviet Union and the end of the Cold War, the United States, which saw itself as the only power, or as Huntington cited the sole superpower, increased its influence in areas previously was controlled by the Soviet Union. Washington initialed its influence by recognizing the independence of countries and granting some economic aid to the region's republics to rebuild their economic situation. The events of September 11 and the "war on terror" provided a better opportunity for a US military-security presence in the region.
The current trend of developments in the international system indicates that a country will play the role of the world's leading power in the 21st Century that can dominate the world's energy resources and pipelines especially. In other words, having control over and access to significant energy resources and markets is an important asset because it enables states to protect vital national interests at home and leverage economic and political influence abroad. States without such assets, by comparison, have less leverage and are more vulnerable. The rapid growth of renewable energy is, therefore, likely to alter the power and influence of some states and regions relative to others and to redraw the geopolitical map in the 21st century. (IRENA, 2019). By the way, needless to mention that, countries that have so far dependent on the Middle Eastern energy have tried to reduce their reliance on the region's oil and gas, especially the Persian Gulf. This is partly because, as mentioned, the United States has claimed that the roots of 9/11 events and beyond are in this region.
Thus, the Caspian Sea and the Central Asian region and the Caucasus play a special role in geopolitics cs of energy. The United States has had several macro-policies and strategies in the region, including "energy security." This includes easy access to the region's energy resources, the geographical diversity of resources and transmission routes, the possibility of stability and non-change in the region's governments, in the long run, control of oil prices, reducing dependence on oil and gas of the Persian Gulf and the establishment of pipelines to transfer energy from various routes (Boute, 2019). Nevertheless, one should bear in mind that the Caspian region's oil could not make the region the second Persian Gulf, nor could it save the region from lagging in terms of development. There are only about 5% of the world's total energy reserves, and this cannot afford the world need, but, anyway, it can be effective.
There is another view that suggests that the great game in the region is over. This means that the Caspian oil fields are not as attractive as the United States was promoting (Mirovaley, 2020;Foust, 2011). Here the fundamental question is: which region is more important in US foreign policy, the Persian Gulf, or Central Asia? Normally, the United States has its own political and military exploits for each event, depending on the situation and time. At the end of the Cold War, one of the main Washington politicalmilitary goals was to expand NATO out of Europe borders towards the East, closer to Russia's borders to monitor Heartland area. The events of September 11, and the "War on Terror" in Afghanistan provided Washington with another golden opportunity to cement its presence in Central Asia. This time, many Persian Gulf countries, Central Asian and Caucasus republics, and the Indian subcontinent provided Washington with bases and military facilities for the fight against terrorism and military strikes against the Taliban government and al-Qaeda forces in Afghanistan.
On the other hand, the United States seeks to further develop and consolidate its power and influence across the world and to decrease the influence of its political and economic rivals in the glob. Washington, indeed, seeks to have a wider and more active presence and s influence in areas of the world that are economically important. In comparing the important regions of Central Asia and the Persian Gulf, this is also worth considering.
After the collapse of the Soviet Union, the United States started influencing the Central Asian region and thus established good relations with the newly independent states to reduce Russia's influence in the region. Also, the US government strongly has supported the American companies operating in the Caspian basin to diversify its oil supply and to keep oil prices low through flee the region's oil to the international markets. David Robson, Executive Chairman and President of Tethys Petroleum, in 2014 expressed that "Central Asia has all of the aspects necessary for it to be a key area for oil and gas. The area is large and contains some extremely prolific oil and gas basin." (Robson, 2014). Washington believed that economic growth in the region's republics would lead to political stability and regional conflicts (Amini, 2003). Another factor that highlights the importance of this region's energy reserves is that they are outside OPEC's sphere of influence.
Nevertheless, one should bear in mind that unless the US finds a way to stabilize international oil markets and decrease the price of oil, the success of the US grand strategy in the twenty-first century is dubious. Volatile high oil prices not only hurt the proper functioning of US-controlled international economic structure but also make it more difficult for the US to manipulate oil producers (i.e., Russia and Iran) and consumers (i.e., China and India) to serve its grand strategy (İşeri, 2009). Generally, the Caspian oil fields have attracted US interest for the following reasons: 1. The quality of oil in the region is good. 2. Most of the extracted oil is exported because the region's countries' needs for oil are relatively low and are expected to remain low. 3. The fact that the countries of the region lack the capital and the technology to proceed independently to the development of these oilfields offers American companies, such as Chevron, considerable investment opportunities (Iftekharul Islam, 2011). 4. Geopolitically, the United States wants to help the economic growth of these republics through the development of their oil and gas industries to reduce their dependence on Russia and to contain Russian monopoly over the region's energy.
In fact, by involving the countries of Central Asia and the Caucasus in the field of its security strategy, Washington, on the one hand, has tried to limit and control China's access to Central Asia's energy resources, and, on the other hand, seeks to tilt the balance against Russia. Also, in the post-Cold War era, America has tried to connect the Caspian region to the Persian Gulf (which is more or less a backyard for the United States).In its new geopolitical perspective, the United States sees the Persian Gulf region and the Caspian Sea as the two main sources of energy globally, which are interrelated in geopolitical and geostrategic roles (İşeri, 2009). But with the importance of energy as the vehicle for the US and other Western industries, the Persian Gulf, which has the largest share of the world's energy resources, is getting more attention. One should be clear that the US sees the Persian Gulf as the most vital region for its oil requirements in the long term. After the events of 9/11, the United States launched the "Greater Middle East" plan and strategy for the entire region. It established its military presence in the region under the pretext of establishing security and fighting against terrorism. The war in Afghanistan to eliminate al-Qaeda and to oust the Taliban and the War in Iraq to overthrow Saddam Hussein were all carried out under the pretext of establishing security and stability in the Middle East and the Persian Gulf (Thimm, 2018). One can assume the importance of the region for the implementation of Washington's Afghanistan and Iraq projects.
The problem that the United States is currently facing is that regarding the security of the Persian Gulf, there is no common view among the region's countries, and they always disagree. In other words, the attitudes of the countries in the region towards the key issues of the region's needs are very different (Ezzati, 2002).
In comparison with the Persian Gulf and Central Asia, in terms of energy resources and geopolitical position and terms of the market, the importance of the Persian Gulf will be much more colorful because: 1. There are two-thirds of world oil and one-third of world gas in the Persian Gulf. The stability of the world economy continues to rely on the steady flow of moderately-priced oil from the Persian Gulf.

Strategically, the Persian Gulf is the only region
with excess production capacity. Therefore, the presence of American forces in the Persian Gulf, in the long run, provides the country's long-term economic goals about Europe and Japan. 4. Easy access to raw materials and markets, Middle Eastern countries, and the Persian Gulf is a good market for West's and East's productions (Torrani, 2019). As for Central Asia, however, the region is important, the prospect of US interests diminishes the region's significance to the country because, in addition to challenges in Central Asia and the Caucasus, the region's energy resources are not large enough to shift the focus of the Persian Gulf, as the major energy source for the West and East Asia (Jaffe, 1998) More importantly, as mentioned above, one of the most obvious importance of the Persian Gulf is easy to access to other areas and global markets.
Meanwhile, from the market point of view, as it can be seen in the above table, the Persian Gulf has a population of about 200 million while the Central Asian population is over 70 million,(see table 8). This can indicate the importance of the Persian Gulf to the West and America. Yet, these reasons do not mean that Washington is indifferent to Central Asia. Brzezinski identifies Russia and China as the two powerful countries with a common border with Central Asian republics and countries that are likely to jeopardize US interests in the region. But he cites Iran, Azerbaijan, Ukraine, and Kazakhstan as countries that must be monitored by the Americans as a weight against Russian and Chinese moves to gain access to the natural resources of the Central Asian region. A country that can dominate Central Asia will be able to change the position of the United States in the Persian Gulf (Lawson, 2004). Yet, it is clear that the United States is seeking to undermine Russia's position in Central Asia and elsewhere in Eurasia, an area which Brzezinski presumptuously depicted as "the chief geopolitical prize for America" (Ersen, 2014). By the way, counter-terrorism, which led Washington to pursue two broad war strategies; war against global terrorism (in Afghanistan in 2001) and the fight against weapons of mass destruction (WMD). And preemptive war (in Iraq in 2003), provided an opportunity for the United States to expand and cement its military presence in Central Asia and the Middle East, thereby gaining direct control over its former rivals, such as China, Russia, and Iran (Byman, 2019, Mueller et al, 2006. To sum up although, Central Asia, as heartland, is has occupied an important position in US global policy, the United States maintains an extensive and continually growing presence in the Middle East, and particularly the Persian Gulf, as a new heartland, the center of the center, and a pivot area, with military, diplomatic, economic and cultural dimensions. History has proven that control of energy supplies is the type of matter that great powers go to war over. As Desert Storm demonstrated, few would question whether access to the vast resources of the Persian Gulf is worth a significant commitment of time and resources. Undoubtedly, the stability of the world economy continues to rely on the security and steady flow of moderately priced oil from the Persian Gulf. The diversification of oil supply through the development of areas like Central Asia may affect the significance of the Persian Gulf over time. (Jaffe, 1998) But the Persian Gulf will require a major Washington security commitment for decades to come. Engagement in Central Asia and the Caucasus alone cannot significantly reduce the need for America's major engagement in the Persian Gulf and to police it. All in all, the Persian Gulf contains longidentified vital US national interests and security more than any other region.

Conclusion
Central Asia is a region of major importance in the current economic sphere as a result of its enormous energy reserves, a strategic position as a link between East and West, space of competition, and reinforcement of the great powers. The Persian Gulf where the effects of geopolitics and the competition between the great powers have been the most salient compared to any other part of the world, including Central Asia. The criterion of power in the 21st century is economic capability at the international level. In this regard, the Persian Gulf region will be one of the most important geostrategic and geoeconomic regions due to this capability.
The United States has always sought to control the Persian Gulf region. The Caspian region supplies 5% of the world's oil, while the Persian Gulf supplies 35 to 50% of its oil. Therefore, the Caspian region is never an alternative to the Persian Gulf. Yet, it can be said that the US attention to both regions, the Persian Gulf and Central Asia, is not only for oil or energy resources but the US is using energy as a means to cement its influence and presence in these regions.
Accordingly, despite the past geopolitical theories that considered the Persian Gulf as a Rimland territory, in new geopolitical theories, the Persian Gulf has become the heartland or center of the center. Consequently, in the balance of future powers, superiority will belong to the power that dominates the geoeconomic regions of the world. In this sense, any country that dominates the Persian Gulf will dominate the world. However, it should be noted that Heartland's expansion from Central Asia to the Persian Gulf does not prevent the United States from being indifferent to its rivals in the region, such as China and Russia.