U.S. intervention in Afghanistan (2001-2021)

After the 9/11 attacks, the global perception of security changed, and terrorist organizations became an international security threat, marking the beginning of asymmetric warfare. U.S. President George W. Bush, with his statement, "You are either with us or with the terrorists," redefined the concept of the enemy in the post-Cold War era, initiating a new period beyond the NATO-Soviet polarization. Although the U.S. intervention in Afghanistan led to the overthrow of the Taliban government, the war continued for 20 years. In 2017, U.S. President Donald Trump decided to withdraw, and in 2021, President Joe Biden completed the withdrawal, officially ending the U.S. military presence in Afghanistan. This marked the beginning of a new era under the Taliban government. However, by maintaining its narratives and justifications for intervention in Afghanistan from 2001 to 2021, the U.S. continues to assert its hegemony through political and economic means both in the region and globally. The security vacuum created after the withdrawal has become a regional and global issue. As a result, international organizations and regional actors are making efforts to address the problem and are conducting international meetings to find solutions. This study analyzes the U.S. intervention in Afghanistan through the lens of liberal security approaches and the theory of perpetual peace. It explains the presence of U.S. hegemony using Antonio Gramsci's concept of hegemony and examines the transformation of U.S. security policies over 20 years. The study argues that the withdrawal from Afghanistan did not signify a military defeat for the U.S. but rather created a new security challenge for powerful rivals such as Russia and China. The study consists of three main sections. The first section, "The Historical Process Leading to International Intervention," discusses theoretical approaches, conceptual analysis, Afghanistan's political structure, and the U.S. presence in the country until 2001. The second section, "U.S. Intervention in Afghanistan and Process Analysis," analyzes the U.S. intervention and its hegemony up to the decision to withdraw. The third section, "Security Challenges Following the U.S. Withdrawal from Afghanistan," explores the end of the U.S. military presence, the security issues that emerged after the withdrawal, and international efforts to find a solution.