The war lasted 14 years and was a fluid situation. Think Vietnam. Many of the ARVN officers had a brother in the Viet Cong, or a cousin in the NVA. Through networks upon networks, more often than not, we and the enemy received our orders, and sometimes their orders, at the same time. There were very few secret secrets.
A former VC, now resident in CA, said to me, "It was like pro football, we always knew exactly what play you were going to run, the only question was if we were good enough to stop it!"