Complex sentence: Stockdale was held as a prisoner of war in the Hoa Lo prison for the next seven and one-half years and as the senior Naval officer he was one of the primary organizers of prisoner resistance.
Split into simpler sentences: Stockdale was held as a prisoner of war in the Hoa Lo prison for the next seven and one-half years. As the senior Naval officer, he was one of the primary organizers of prisoner resistance.