What began as a military aid program by the United States in 1950 to assist the French in subduing communist rebels in French Indochina

French Indochina

French Indochina was part of the French colonial empire in southeast Asia. A federation of the three Vietnamese regions, Tonkin , Annam , and Cochinchina , as well as Cambodia, was formed in 1887....

, became, by 1965 an all-out war between South Vietnam

South Vietnam

South Vietnam was a state which governed southern Vietnam until 1975. It received international recognition in 1950 as the "State of Vietnam" and later as the "Republic of Vietnam" . Its capital was Saigon...

 and North Vietnam

North Vietnam

The Democratic Republic of Vietnam , was a communist state that ruled the northern half of Vietnam from 1954 until 1976 following the Geneva Conference and laid claim to all of Vietnam from 1945 to 1954 during the First Indochina War, during which they controlled pockets of territory throughout...

 in which the United States was deeply involved. The United States Air Force

United States Air Force

The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 was deployed to South Vietnam as part of this effort.

Throughout the war in Vietnam, subordinate USAF commands there operated under the jurisdiction of United States Pacific Air Forces in HAwaii.
What began as a small US military assistance program to South Vietnam, grew into a wider regional conflict.