This book recounts the experiences of a young US Marine officer during the Vietnam War as he fights that war over a nineteen month period in three different geographical areas of South Vietnam. He graphically explains to the reader what it was like to perform three distinct combat missions: long-range ground reconnaissance in the Annamite Mountains of I Corps, infantry operations in the rice paddies and mountains of Quang Nam Province, and special police operations for the CIA in Tay Ninh Province. The author describes in rich detail each of these distinct military activities and provides powerful and explicit examples of each. Using primary sources, such has US Marine Corps official unit histories, CIA documents, and his weekly letters home to his parents, the author relies almost exclusively on primary sources to convey to the reader a story that is devoid of hyperbole and focused on providing an accurate and honest account of combat at the small unit level. Of particular interest to students of the war is his description of his assignment to the CIA as a Provincial Reconnaissance Unit (PRU) advisor in Tay Ninh Province, where he participated in several secret missions as part of the controversial Phoenix Program. He also reveals the name and contribution of the CIA’s most valuable spy during the war, the famous Tay Ninh Source .