 Complete the following phrase:  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 Brigades deployment to Afghanistan in 2002-2003 in support of 