In 1965, soon after the first US combat troops had arrived in Vietnam, it was realized that in some areas the Viet Cong had developed vast tunnel complexes in which to hide from the enemy. This title describes the specialist training and equipment of those who fought an underground war against the Viet Cong in Vietnam.

Gordon L Rottman entered the US Army in 1967, volunteered for Special Forces and completed training as a weapons specialist. He served in the 5th Special Forces Group in Vietnam in 1969-70 and subsequently in airborne infantry, long-range patrol and intelligence assignments until retiring after 26 years. He was a Special Operations Forces scenario writer at the Joint Readiness Training Center for 12 years and is now a freelance writer, living in Texas.