Complex sentence: During his first enlistment heserved primarily as a coxswain, but when he re-enlisted in 2003 he specialized in security operations; in particular Detainee Operations in Iraq and Protective Services Details.
Split into simpler sentences: During his first enlistment he was a coxswain, but when he re-enlisted in 2003 he specialized in security operations. In particular Detainee Operations in Iraq and Protective Services Details.