he War in Afghanistan, which began on October 7, 2001 as the U.S. military operation Operation Enduring Freedom, was launched by the United States with the United Kingdom in response to the September 11, 2001 attacks. The stated purpose of the invasion was to capture Osama bin Laden, destroy al-Qaeda, and remove the Taliban regime which had provided support and safe harbor to al-Qaeda.
Two military operations in Afghanistan seek to establish control over the country. Operation Enduring Freedom (OEF) is a combat operation involving coalition partners led by the United States against Al Qaeda remnants, primarily in the eastern and southern parts of the country along the Pakistan border. OEF is not a NATO operation, although some coalition partners are NATO members. Approximately 20,000 troops are in OEF, including approximately 18,000 U.S. forces. The second operation is the International Security Assistance Force (ISAF), established by the international community in 2002 to stabilize the country. NATO assumed control of ISAF the following year. By Nov 2008, ISAF had around 50,700 troops from 41 countries, with NATO members providing the core of the force. The United States has approximately 17,000 troops in ISAF.
The U.S. and the UK led the aerial bombing campaign, with ground forces supplied primarily by the Afghan Northern Alliance. In 2002, American, British and Canadian infantry were committed, along with special forces from several allied nations. Later, NATO troops were added.