This official history recounts an ambitious attempt by the Air Force to interdict traffic on the Ho Chi Minh Trail of southern Laos, as part of a plan to support the war in South Vietnam by impending the flow of North Vietnamese troops and military supplies into South Vietnam. Secretary of Defense Robert S. McNamara intended initially to establish a manned barrier guarding the demilitarized zone between the two Vietnams, while using electronic sensors and computers to detect and analyze movement on the Ho Chi Minh Trail so that aircraft could attack the troops and cargo bound for the...