In 2000, Frost was assigned to the 82nd Airborne Division at Fort Bragg, North Carolina where he served as the Division Training Officer and Operations Officer for both the 3rd Battalion, 504th Parachute Infantry Regiment (PIR) and 1st Brigade (504th PIR). His tour as Brigade Operations Officer was highlighted by 1st Brigade's deployment to Afghanistan in 2002-2003 in support of Operation Enduring Freedom. From December 2002 to May 2003, the brigade was the U.S. Army's sole combat brigade in Afghanistan. It conducted over a dozen Brigade Air Assault operations, numerous Ground Assault Convoy operations, and several Air Drop and Civil Military operations. Under the theatre level Combined Joint Task Force 180 and the subordinate Combined Task Force 82, the brigade operated with numerous coalition and special operations partners against al-Qaeda and the Taliban.