Why did war in Afghanistan happen?

The war in Afghanistan began in response to the September 11, 2001 terrorist attacks orchestrated by al-Qaeda, which was based in Afghanistan and protected by the Taliban regime. The U.S. aimed to dismantle al-Qaeda and remove the Taliban from power to prevent future terrorist activities. Additionally, the conflict was influenced by broader geopolitical interests, including concerns about regional stability and counterterrorism. The ensuing war led to a prolonged military engagement and significant changes in Afghan society and governance.