Introduction: The hasty and chaotic withdrawal of US forces from Afghanistan hastened the Taliban’s return to power in Kabul and revived old fears of contagion of conflict and terrorism to neighboring countries. In this regard, compared to the 1990s, the Taliban today are linked to international jihadist networks, and the Taliban’s goal remains the same as it was in the 1990s: to capture Kabul and establish an Islamic emirate based on Sharia. Therefore, Taliban dominance does not seem to guarantee peace. In fact, it could signal the emergence of a new wave of hostility and radicalization. Insofar as Afghanistan is a country fractured by ethnic, tribal, and religious divisions and has been at the center of geopolitical competition for centuries. On the other hand, despite the agreement between the US and the Taliban to prevent the activities of terrorist groups on Afghan soil, the Taliban have intensified their attacks on rural areas of several provinces, especially in northern Afghanistan, and have taken control of key border crossings and areas bordering Iran, Turkmenistan, and Tajikistan. These issues raise theoretical challenges and make it necessary to examine the challenges of Talibanism gaining power around the member states of the Shanghai Cooperation Organization.
Theoretical framework: The regional security complex theory not only presents the internal dynamics of regional systems as an independent whole, free from the effects of both macro (international system structure) and micro-level variables, but also has the ability to explain the dynamics of different regional systems. Buzan and Weaver define the regional security complex as: “a set of units in which their major processes of securitization and de-securitization are interconnected and whose security problems cannot be
 
logically analyzed or solved in isolation.” Hence, it can be argued that the regional security complex theory is fundamentally based on the concept of security dynamics and regional models. The main structure of this theory is formed by state-to-state relations across a geographical boundary that give rise to the region as it is. This is important insofar as political and military threats are more powerful in creating a sense of insecurity than other threats to state insecurity, which is related to geographical proximity. The center of gravity of the regional security complex theory is that security threats more easily affect nearby areas than those at greater distances.
Methodology: The present research method is descriptive-analytical and the data collection tool is library, document and internet studies. The methodological framework of this article is a qualitative study, considering the research topic and the theoretical framework. The qualitative analysis method emphasizes on the text that expresses the realities of the challenges of the Shanghai Cooperation Organization. At the same time, it is practical in terms of purpose. So that the theoretical framework based on the regional security complex used in this research has become significantly popular in regional studies today. To the extent that it has been fruitful for descriptive and analytical purposes by referring to it. From this perspective, the present thesis uses description as a method in identifying theoretical concepts and definitions of existing literature and uses analysis in operationalizing the impact of the Taliban's re-empowerment on the Shanghai Cooperation Organization.
Results & Discussion: Today, regional powers increasingly describe Afghanistan as an isolated country in terms of military, economic, demographic, political and ideological resources to project power in the regional security complex, and also as a connecting country due to its unique geostrategic location at the crossroads of Central Asia, South Asia and the Middle East, which has led to permanent instability, which has stemmed from internal power struggles and external interference and attempts to control Afghanistan.
Since the 1990s, threats from Islamic extremists have become a common theme in the SCO region’s cooperation. As indigenous economic and physical constraints and regressive political developments hinder progress towards a new regional economic entity, the return of Taliban rule to Afghanistan would have important implications for the region and international politics more broadly. More generally, the potential challenges that a Taliban-ruled Afghanistan might pose to the security and regional interests of SCO member states are significant for the development of long-term cooperation. With the Taliban’s return to power in Afghanistan following the US withdrawal, there has been growing speculation about what this could mean for neighboring countries. Indeed, the SCO’s primary concern has been to contain the spread of terrorism, extremism and separatism in SCO member states. The Taliban’s dominance in Afghanistan has been seen as a key base for Islamic extremism, with many extremists and Islamic terrorists being trained in the country. Cases that cause the member states of the Shanghai Cooperation Organization to face crises in order to develop cooperation and pose numerous challenges for the member states of the Shanghai Cooperation Organization, such as political-security, economic, border disputes, refugees, and ideological challenges.
 
Conclusions & Suggestions: Given the confrontation between the United States and the powerful SCO countries and many objective issues, more opportunities have been created for the SCO, which can become one of the most effective international organizations on the Eurasian continent. To this end, the SCO must resolve some internal issues that pose major obstacles to the further development of the organization. In particular, with the beginning of a new stage in the development of the SCO through the attraction of new members, a topic that includes the development of capabilities in the field of regional security has emerged. In fact, the expansion of the organization provides an opportunity to significantly optimize the task of cooperation in the field of regional security around countering terrorism, extremism, transnational crime and illegal drug trafficking. This is in the interests of all member states. Due to the overlapping borders of the countries with Afghanistan and the economic interdependence that is supposed to create a regional open market system, Afghanistan will have a great contribution to its neighbors if it is stable and prosperous.