Extended Abstract

Introduction: Since the emergence of the Taliban in Afghanistan in the 1990s, developments in this country have had significant security and political implications for Iran. The rise of the Taliban and their eventual capture of Kabul in 1996 confronted Iran with a movement characterized by a radical ideology, anti-Shia orientation, and close ties to actors that threatened Iran’s interests. The killing of Iranian diplomats in Mazar-i-Sharif in 1998 further intensified tensions, leading Tehran to support the Northern Alliance and seek to contain the Taliban without resorting to direct military intervention. Following the Taliban’s overthrow in 2001, Iran cooperated with the United States in establishing a post-Taliban political order and maintained constructive relations with successive Afghan governments. However, the return of the Taliban as a significant political and military actor, the growing U.S.–Iran rivalry, and particularly the emergence of ISIS-Khorasan gradually altered Tehran’s calculations and encouraged a more pragmatic engagement with the Taliban. The Taliban’s return to power in August 2021 subsequently created a new phase in Iran–Taliban relations, characterized by cautious interaction and security cooperation. Against this background, security considerations have remained central to Iran’s policy toward Afghanistan, encompassing border security, terrorism and extremism, drug trafficking, and migration. The present study aims to analyze the role of these security considerations in the transformation of Iran’s foreign policy toward the Taliban from 1990 to 2026, focusing on the problem of how changing security conditions have shaped Iran’s movement between confrontation, balancing, and pragmatic engagement.

Research Question: How have security considerations influenced the transformation of Iran’s foreign policy toward the Taliban?

Research Hypothesis: The hypothesis is that the transformation of Iran’s foreign policy is a function of the redefinition of threat perception; accordingly, in confronting ideological threats and border insecurity during the Taliban’s first period of rule, Tehran adopted a confrontational deterrence approach, whereas during the period of U.S. presence and the emergence of ISIS-Khorasan, it shifted its strategy toward pragmatic engagement to contain terrorism and consolidate border security, a strategy that continued after 2021..

Methodology (and Theoretical Framework if there are): The research uses a qualitative approach based on process tracing to examine Iran’s foreign policy toward the Taliban from 1990 to 2026. Process tracing reconstructs historical developments chronologically, identifies events and actors’ decisions, and explains causal mechanisms linking security conditions to policy outcomes. The study divides this period into three phases: the first Taliban rule (1990–2001), the U.S. occupation (2001–2021), and the second Taliban rule after 2021. The analysis is guided by defensive realism, which views security rather than power maximization as the primary state objective and emphasizes the balance of threat. Accordingly, Iran’s policy is interpreted as a response to changing threats, leading Tehran to alternate between balancing against the Taliban and cooperating with them against threats like ISIS-Khorasan.

Results and discussion: According to the findings, Iran's security considerations played a key role in determining the extent of cooperation or competition with the Taliban. Iran has sought to ensure national security and prevent the influence of its opposition groups in Afghanistan and this issue has led to it taking action against the Taliban with other actors, even the US government, at times like the 1990s and 2001 and then, due to changing security threats, it interacted with the Taliban and even coalified with this group against ISIS-Khorasan. Iran's security concerns, including the spread of terrorism, the influence of extremist groups, and border security threats, as well as drug trafficking and migration, have played a significant role in changing Iran's foreign policy toward the Taliban. In Afghanistan, Iran has sought to reduce threats emanating from Afghanistan rather than gain a strategic advantage. Even when its diplomats were killed in the first Taliban government, Iran did not act aggressively against them and tried to create a balance with other partners against the Taliban. It was security issues that transformed and turned Iran's policy towards the Taliban. This research shows that Iran has taken a cautious approach to the Taliban, pursuing a combination of cooperation and competition to meet its security interests.

Conclusion: Iran's foreign policy towards the Taliban, from the 1990s to 2025, has undergone a gradual shift towards interaction and cooperation, taking into account security factors such as drug trafficking, the refugee crisis, the presence of unfriendly governments in Afghanistan, ISIS Khorasan, and with the aim of preserving national interests and regional stability, but maintaining red lines and not fully accepting the Taliban remains on the agenda. This analysis shows that in the period 2021-2025, by utilizing the principles of defensive realism, Iran has been able to prevent Afghanistan from becoming a security threat while at the same time securing some of its economic and political interests. To control security threats, Iran must engage with the Taliban and never provoke them. As a result, it must place ideological issues in second place and adopt a pragmatic approach towards the Taliban. Iran's inaction in establishing a strong relationship with the Taliban leaves Iran's rivals in the country open, and Iran is deprived of Afghanistan's human and natural resources. To reduce the threat, Iran should strengthen water diplomacy with the Taliban, develop border security mechanisms, and diversify relations with different Afghan factions.