As part of the War on Terror, the United States drove the Taliban out of power.
The War on Terror was a military campaign initiated by the United States after the September 11th attacks. Although the aim of the U.S. was to capture all of al-Qaeda members, most of them got to escape. The action of the United States was negatively encouraged by the Taliban government, which did not accept to extradite Osama bin Laden nor contributed to shut down the terrorist bases. As a result, the United States, that counted on the United Kingdom and other allies, drove the Taliban out of power and built military bases in the country.