Why did the Afghanistan war begin?

The Afghanistan war began in October 2001 in response to the September 11 terrorist attacks orchestrated by al-Qaeda, which was harbored by the Taliban regime in Afghanistan. The U.S. and its allies aimed to dismantle al-Qaeda and remove the Taliban from power to prevent further terrorism. The conflict was framed as part of a broader "War on Terror" initiated by the U.S. government. The invasion sought to establish a stable government in Afghanistan and prevent the country from being used as a base for future terrorist activities.