Complex sentence: John left the Pentagon in 1995 and became a consultant for various corporate interests, then became a founding partner of RRR Consulting in the early 2000's and later on, a co-founder of Pace-Capstone a government affairs and strategic development firm.
Split into simpler sentences: John left the Pentagon in 1995 and became a consultant for various corporate interests, before becoming a founding partner of RWR Consulting in the early 2000's. Later on, John was a co-founder of Pace-Capstone, a government affairs and strategic development firm.