War in Afghanistan (2001-2021)

What happened

The War in Afghanistan (2001-2021) began with the U.S. invasion to pursue Al-Qaeda and overthrow the Taliban. Initial U.S. military success quickly defeated Taliban forces and established a U.S.-backed government. However, the Taliban regrouped and waged a persistent insurgency. The war gradually escalated, with NATO allies (Britain, Germany, Canada, Australia) deploying forces. U.S. troop levels peaked at 100,000 (2010-2011). The war involved counterinsurgency operations, drone strikes, and attempts to build Afghan military and government capacity. Despite two decades of effort and $2 trillion spent, the Taliban remained effective. U.S. withdrawal accelerated under Trump and Biden administrations. By August 2021, the Taliban conquered the capital Kabul and re-established control over Afghanistan.

Why it mattered

The Afghanistan War demonstrated the limits of U.S. military power against determined insurgency motivated by nationalist and religious fervor. The war's failure undermined U.S. credibility and revealed overconfidence in military solutions to political problems. The Taliban's victory validated arguments about avoiding long-term military interventions in complex political environments. The war's end enabled the U.S. to focus on China as the primary strategic competitor. Afghanistan's return to Taliban control disrupted U.S. strategy in Asia and enabled the Taliban to provide safe haven to various militant groups.