Complex sentence: The KCIA's original charter, Act Concerning Protection of Military Secrets, was designed to oversee the coordination of activities related to counterespionage and national security, but a majority of its activities and budget were devoted to things unrelated to its original charter.
Split into simpler sentences: The KCIA's original charter, Act Concerning Protection of Military Secrets, was originally designed to oversee the coordination of activities related to counterespionage and national security. Needless to say, a majority of its activities and budget were devoted to things unrelated to its original charter.