Operation Igloo White, a US electronic surveillance system to stop communist infiltration into South Vietnam begins installation.

Operation Igloo White was a covert United States joint military electronic warfare operation conducted from late January 1968 until February 1973, during the Vietnam War. These missions were carried out by the 553rd Reconnaissance Wing, a U.S. Air Force unit flying modified EC-121R Warning Star aircraft, and VO-67, a specialized U.S. Navy unit flying highly modified OP-2E Neptune aircraft. This state-of-the-art operation utilized electronic sensors, computers, and communications relay aircraft in an attempt to automate intelligence collection. The system would then assist in the direction of strike aircraft to their targets. The objective of those attacks was the logistical system of the People's Army of Vietnam (PAVN) that snaked through southeastern Laos and was known as the Ho Chi Minh Trail.

The People's Army of Vietnam (PAVN), officially the Vietnam People's Army, also recognized as the Vietnamese Army, the People's Army or colloquially the Troops, is the national military force of the Socialist Republic of Vietnam and the armed wing of the ruling Communist Party of Vietnam (CPV). The PAVN is the backbone component of the Vietnam People's Armed Forces and includes: Ground Force, Navy, Air Force, Border Guard and Coast Guard. Vietnam does not have a separate and formally-structured Ground Force or Army service. Instead, all ground troops, army corps, military districts and special forces are designated under the umbrella term combined arms and belong to the Ministry of National Defence, directly under the command of the CPV Central Military Commission, the Minister of National Defence, and the General Staff of the Vietnam People's Army. The military flag of the PAVN is the National flag of the Socialist Republic of Vietnam defaced with the motto Quyết thắng added in yellow at the canton.

South Vietnam, officially the Republic of Vietnam, was a country in Southeast Asia that existed from 1955 to 1975. It first garnered international recognition in 1949 as the associated State of Vietnam within the French Union, with its capital at Saigon. Since 1950, it was a member of the Western Bloc during the Cold War. Following the 1954 partition of Vietnam, it became known as South Vietnam and was established as a republic in 1955. South Vietnam was bordered by North Vietnam to the north, Laos to the northwest, Cambodia to the southwest, and Thailand across the Gulf of Thailand to the southwest. Its sovereignty was recognized by the United States and 87 other nations, though it failed to gain admission into the United Nations as a result of a Soviet veto in 1957. It was succeeded by the Republic of South Vietnam in 1975. In 1976, the Republic of South Vietnam and North Vietnam merged to form the Socialist Republic of Vietnam.