In Vietnam the United States is involved in the longest war in its nearly 200-year history. The introduction of American advisors in the late '50s and the significant build-up that occurred in the early '60s signalled the US commitment to insure South Vietnam's right to independence. In 1965 American troops began arriving in large numbers and assumed the primary combat role. During the next two years the US soldier fought major battles unlike all previous conflicts. He also began the task of preparing the South Vietnamese to take over the combat role. The most formative years of this role actually began in 1967, when the North Vietnamese Army's ability to control the countryside was curtailed. American and South Vietnamese forces took the offensive, lost it momentarily in early 1968, and then regained it again late that year. They never lost it again, while rooting out and neutralizing the Viet Cong Infrastructure, defeating the North Vietnamese on the open battlefield, and destroying the supply areas in Cambodia and Laos. The story of these important years is related here in these pages by the men who led and the soldiers who fought, and is told as only they can tell it.