The end of Cold War was a watershed in the annals of International Relations. It marked the end of an era of international relations as whole. It also marked the end of twentieth century which witnessed two World Wars followed by the Cold War. The emerging century changed the paradigms of international relations. The news trends in international relations would have consequential effects on the security of the states. Since the start of civilization, the most important concern of the human beings is the concept of security. Human beings toil for the shelter against the threats they face. With the passage of the time the concept of security took a mutation. The concept of security changes unabatedly. In the beginning, human sought protection against the harsh weather; against the wildlife attacks and against the natural disasters. With the advancement in technology, this concept has transformed. Humans can protect themselves against the extreme weather conditions; against wildlife attacks and against the natural disasters. Now, the concept of security took different shapes. Now, the individuals need to protect themselves against the other individuals; individuals against the society; society against the state and states against states. To put it simple, security is a constructive and subjective phenomenon which is developed and propagated by the states. It may also be stated that security is a phenomenon under which the state is set free from the threat of danger or extinction. “Security is a pursuit of freedom from threat and the ability of states and the societies to maintain their independent identity and their functional identity against the forces of change which they see as hostile.” In other words, to equate security with survival will not be erroneous. The concept of security ranges from individual to state; from state to region and finally from region to international level. Many a theory has defined the concept of security. But this concept is often associated with Regional Security Complex Theory propounded and propagated by Barry Buzzan and Ole Weaver. They proposed this theory in 2003 in their work ‘Regions and Power: The Structure of International Security’. This theory is based on constructive and subjective approach. A regional security complex can be explicated as a group of states whose fundamental concern is security which is linked in such a way that national security of one state is linked with the security of another state. The security of one state cannot be considered apart from the other state. Barry Buzan and Ole Weaver consider world as a cluster of different geographical regions. This theory helps to analyze and compare the security of different regions. The fault line of this theory shows that securities are interdependent within the regions not between the regions. The widening of international relations has incorporated traditional security approaches along with non-traditional security approaches. The Copenhagen School is eminent in contributing to such studies. This attempt has further broadened the horizon of the scope of the security studies and world politics. Barry Buzan is often regarded as the father of this school of thought. Three approaches have been taken by this very school of thought which are; securitization, sectoral approach to security and Security complex theory. Regional Security Complex Theory explicates that how the concept of security is shaped in geographical regions. The security of the regions is inextricably attached to one another. Insecurity of one causes the insecurity for the other. Security complex is the synthesis of neo-realism and globalism. It incorporates systemic and state level of analysis. It also adds the regional level of analysis and considers both state as well as non-state actors in conceptualizing the security complex. Buzan and Weaver further explore the chief concept of the Regional Security Complex Theory by saying that threats travel at a shorter distance more easily than a longer one, therefore, security is more complex within the actors inside the geographical regions instead of outside it.RSCT emerges on the platform of the theories at very crucial time. It was a time when other theories failed to answer the question of the emerging order after the Cold War. Cold War witnessed a rivalry between the two super powers; USSR and US. With the end of the Cold War, USSR cringed back to its eastern hemisphere and the US emerged as a sole power, which had a claim to call the world a unipolar. United States started claiming herself as the policeman of the world. RSCT has dared to answer the questions rising the post-cold war period. The theory has described the post-cold war world as not merely a power play of the US but the assembly of many regional powers along her. After the cold war period RSCT explains the behavior of the regional powers and the super powers in the magnificent way. It shows that1. World powers started showing disinterest in the affairs of the other countries. They also show less interest to intervene in the matters of the world. 2. New powers had begun to develop, which evinced less interest in military engagements and security competitions at the end of the cold war and remained aloof from the influence of the big powers. The post-cold war era, as it has been discussed above, witnessed less number of intensified conflicts. The bipolarity was shifted to the unipolarity of the world. Now the super power in the unipolar world seemed disinterested in the matters of the other regions. Owing to the shift in the polarity, there was reduction in the intensity of the global concerns and the reduction in the sources available. Now the influence of the relations has been fallen on the region. There was a concept of amity and enmity in the relations among the units of the regions. It has been further explained that such phenomenon of amity and enmity is not natural among the units. It has some basic conditions which provide a plank on which structure of this relation is erected. According to regional security complex theory (RSCT) four levels of analyses are:1) State level of analysis defines the security at the state level. The vulnerabilities and threats which engender fear in state. Other states also constitute a threat for a state. 2) Regional level of analysis include state to state relations at regional level. Different states constitute to form a region. 3) Inter-regional level of analysis incorporates the role of other regional powers. It shows the involvement and interplay among different regional and global powers. 4) Globalsystemic level of analysis shows that how the regions interact with other regions and neighboring powers. It is the involvement of different powers in a region and make it a systemic level of interaction.The theory of RSCT is highly dependent upon the areas where it has been applied. RSCT can be applied in different manner in different regions. The propagators of RSCT have considered almost all the regions of the world. The application of the theory is dependent upon the condition of amity and enmity of in a region. This theory will be applied differently in Middle Eastern region as compared to Asia. In Middle East, there is a still struggle for dominance. Whereas, in South Asia the concept of threat is antithetical to Middle East. In Europe, security threats are less intensified because of more interdependent economic structure. Moreover, RSCT applies differently in African continent. Nigeria and South Africa are the chief architects of the African security. As it has already been mentioned above that the concept of security is dependent upon the concept of amity and enmity which is different everywhere. Regionalism is the basis of the theory of RSC. Regions were not much visible on the globe before the process of decolonization. Before the start of the cold war, the entire world was a battle ground. Big powers were fighting each other for more power. In cold war era two major blocs; USSR and USA were militating against each other to extend their sphere of influence. Eventually, the post-cold war era witnessed the process of decolonization. Eastern powers had to lick the dust while the western powers emerged triumphant. Emerging states started falling into compacts and alliances to secure themselves against any security threat. OIC, NAFTA, EU, SAARC, BRICS, ECO can be categorized as the glaring examples of such alliances. To put it simple, the propagators of the theory of RSC put forward the concept of securitization and presented a finer picture of securitization. The process of securitization stems from the realistic school of thought. This can be viewed succinctly in the following points:1. There is no overarching authority in the international arena to resolve the resulting from the interaction among the states. 2. In the international system, states interact with one another but they are different from each other. They represent different regions, therefore, interaction results into complexity.3. States are the units composed of different sub-groups and organizations.4. There are other sub-groups within the units. These sub-groups are bureaucracy.5. In sub-groups, there are individuals to run the affairs. RSCT discusses different levels of analyses at length. First, it is the system level under which states interact with one another. When there is interaction, conflict is bound to occur. Therefore, in realistic point of view, there is anarchy at the system level. There is no government on the international level to resolve the conflicts. Thus, security issues are destined to be occurred at the system level. Then comes the subsystem level, at this level, there are different regions. These regions come into being with the help of the states. Different states combine to form a region. These states are formed with the help of subgroups and different organizations. These organizations can be named bureaucracies. These institutions are the structural combination of these states. There are also multi-national corporation (MNCs). These MNCs have a great influence in the policy making of a state. Thus, the securitization of a state can be viewed through different lenses. The phenomenon of securitization starts from the state level and goes up to the system level. There are three concepts of RSC which can define the concept of securitization along with hegemonic structure. First, the states which are globally hegemon have tendencies to establish hegemony over the regions. Then, there are regions which are connected through the economic institutions like EU. Finally, unstructured concept of the states, where states are too weak to remain independent. Therefore, security interdependence is the result from the interplay of the states and the regions. RSCT has rightly claimed the securitization process as a by-product of the relations of the states at the regional level. Region has been given great importance in RSCT. The theory of RSC can be analyzed at various levels; at domestic, regional and systemic level. It should be contained in mind that all are inextricably attached with one another. All levels of analyses are co-relational. Region is a prerequisite to the system level. If hegemony is to be established at systemic level; first, it is necessary to be a hegemon at regional level. Theory of RSC has overtones of realism. Both theories are the products of pessimistic thought. Like realism, RSCT put emphasize on the anarchical structure at the global level. The anarchical structure impacts the behavior of the states. It impedes cooperation among the states; therefore, fosters the concept of amity and enmity among the states. The process of enmity and amity can be dated back to the distant historical and cultural discrepancies among states. RSCT expounds that the securitization of the regions depends upon the interdependence of the states. The glaring example of this can be found in Middle East. States are interdependent on each other in such a complex manner that securitization of one state follows by securitization of another state. Several components of security can be explained under following points:1. International system, which is anarchical in nature.2. Units vary in their arrangement and importance.3. There is succinct pattern of amity and enmity among the states.4. Distribution of powers among the states, which is different with regards to each state. Regional security has started gaining importance with regards to securitization. Like global security, regional security has become an important factor around which the policies of most of the countries revolve. Neutral regions cannot be sited as security regions but they have their own importance like European Union. Security threats travel from one place to another. Nowadays, terrorism bespeaks such travelling security threats. While analyzing security threats at regional level (sub-systemic level), security threats at global level (systemic level) cannot be excluded. The interference of extra-regional powers gives rise to security issues at regional level. That is why some neutral regions become unable to play a role of neutrality and becomes an agent of fomenting security threats. This theory, as discussed above, states that security threats travel brusquely at shorter distance as compared to longer distance. It can be viewed in the Indo-Pak rivalry since the inception of the states. Both countries are headstrong enemies of each other. India and Pakistan fought their first war in 1948 even before the involvement of great powers. India wanted to undo Pakistan at any cost and Pakistan fought for Kashmir’s independence. Both countries perceived threats and reacted to the threats in a formidable manner. It vindicates the assumption of the RSCT that security threats travel at shorter distance more abruptly than at longer threats. This theory can best be applied in case of South Asia. Interestingly, Barry Buzan and Ole took South Asia as the case study to develop their theory of Regional Security Complex. The region of South Asia consists of seven states. These states are different in their sizes and capabilities. These states are also vulnerable to the security threats at intra-states, interstates and human levels. These threats incorporate not only traditional but also non-traditional concepts of security threats. South Asia is home to more than 1/5th of the world’s population. This region is considered as the most populous region in the world. Furthermore, its geographical location adds up to its importance and that is why 21st century is often regarded as an Asian century.Bill Clinton, the former president of the United States, called South Asia “the world’s most dangerous place.” There is litany of reasons due to which this region is considered as region of chief importance. With the Nuclear test by India and Pakistan, this region has become more volatile and vulnerable. Its geo-strategic and geo-economic location has attracted the sight of the big powers during the world’s three major eras; during the cold war, post-cold war and post 9/11. Two major countries are bases of the volatility of the region; India and Pakistan. India exerts herself as the hegemonic power because of her ever-growing economy, long-standing army, stable democratic system, and highly educated middle class. This claim of India incites Pakistan to balance Indian mounting threat. Therefore, Pakistan exerts herself as nuclear power. Pakistan has to its credit a well-trained and well-equipped army, growing population, geo-strategic location and economic relations with China. This helps Pakistan not only to counter Indian rising hegemonic threat but also invites the interests of big powers to the region. The issues which are faced by this region are mostly stemmed from the complex internal conflicts. These complex issues are further exacerbated by the by the involvement of external factors. The post 9/11 scenario has brought some clear changes to the complexities of the region. The region has become more complex with the involvement of extra-regional powers. Before 9/11, Pakistan was not enjoying amicable relations with the United States but after 9/11 new trends were witnessed in the relations. Pakistan and the United States involved in direct alliance in their fight against terrorism. As it has been discussed above that two states have far-reaching effects in the future trends of the South Asian region. India and Pakistan are arch-rivals. Both share the same borders and hold Nukes. Both States have some inter and intra-state complexities. There are communal riots in India and insurgencies in Pakistan which ultimately lead to external conflicts. Intra-state conflicts lead to inter-state conflicts, when India blames Pakistan of inciting attacks in Indian territory and Pakistan reiterate in the same and castigate India of inciting insurgencies in Baluchistan. It would not be erroneous to say that most of the external conflicts in South Asia are the result of unresolved internal conflicts. While talking of South Asia, the role of the super powers cannot be overlooked and set aside. The involvement of super powers has served as a catalyst to prolong and sustain the existing situation of enmity in South Asia. Historically, both Pakistan and India took no time to choose sides. During the Cold War period Pakistan sided with the United States and India sided with the erstwhile USSR. After the incident of 9/11, United States remained active in this part of the world. Pakistan was left with no other choice except siding with the United States in war against terror, which further exacerbate the internal complexities. Not only the Indo-Pak relations are the key factor of destabilized South Asian region but Sino-Indian relations also play an important role in determining the instability in South Asia. Border issues between India and China and Sino-Pakistan amiable relations further complicate the region. India considered China’s rise as a threat against its security. Therefore, to thwart the Chinese threat India adds more arms to its military arsenals. China, on the other side, denies all such allegations. Despite China denies such moves by China and Indian response to the moves further jeopardized the already instable region of South Asia. The dynamics of this region are the result of the security complexities which are emanating in the wake of the interaction among the countries. The conception of enmity and amity results into security complexities. India considered China a threat and so as China regarded India. United States also support India to curtail China’s rise. Thus, this creates the security challenge for China. Therefore, China to thwart Indian security challenge, bolsters Pakistan capabilities to thwart Indian challenge. So, the security is not circumscribed to this region only but also invites the extra regional or global powers in it. Thus, Barry Buza’s concept of Regional Security Complex is best applicable in this regard. The security complexities of South Asia initiate from domestic level to regional level of South Asia where India and Pakistan perceives threats from each other. This complex incorporates China as well, who has adversarial relations with India. Finally, at systemic level the United States gets involved in the region and makes the region more complex.