Question

why did the US send troops to overthrow afghanistan's government in 2001

Answer 1

Afghanistan War,

Afghanistan: anti-Taliban fighters [Credit: Reuters NewMedia Inc./Corbis]
international conflict in Afghanistan beginning in 2001 that was triggered by the September 11 attacks and consisted of three phases. The first phase—toppling the Taliban (the ultraconservative political and religious faction that ruled Afghanistan and provided sanctuary for al-Qaeda, perpetrators of the September 11 attacks)—was brief, lasting just two months. The second phase, from 2002 until 2008, was marked by a U.S. strategy of defeating the Taliban militarily and rebuilding core institutions of the Afghan state. The third phase, a turn to classic counterinsurgency doctrine, began in 2008 and accelerated with U.S. Pres. Barack Obama’s 2009 decision to temporarily increase the U.S. troop presence in Afghanistan