NATO ISAF sent troops in January 2002. ISAF took command in 2003.
"Deployed in 2001 – initially under the lead of individual NATO Allies on a six-month rotational basis – ISAF was tasked, on the request of the Afghan government and under a United Nations (UN) mandate, to assist the Afghan government in maintaining security, originally in and around Kabul exclusively. NATO agreed to take command of the force in August 2003 "