 Kirklin was then assigned to the 1st Cavalry Division, at Fort Hood, from 2000 to 2002, where he was the Executive Officer in the 215th Forward Support Battalion, 3rd Brigade Combat Team, 1st Cavalry Division, and 1st Cavalry Division DISCOM S3.His following assignment was as the Course Director, Combined Captains Career Course, at Fort Lee, Virginia, from 2002 to 2004.In 2004, Kirklin returned to Fort Hood, and was again assigned to the 1st Cavalry Division DISCOM, as Deputy Commander while deployed to Taji, Iraq, during Operation Iraqi Freedom.