Nguyn Khnh ([wi kan]; 8 November 1927 11 January 2013) was a South Vietnamese military officer and Army of the Republic of Vietnam general who served in various capacities as head of state and prime minister of South Vietnam while at the head of a military junta from January 1964 until February 1965. He was involved in or against many coup attempts, failed and successful, from 1960 until his defeat and exile from South Vietnam in 1965. Khnh lived out his later years with his family, in exile in the United States, and died of pneumonia and end-stage kidney failure at a hospital in San Jose, California, on 11 January 2013.

The Army of the Republic of Vietnam (ARVN; Vietnamese: Lục quân Việt Nam Cộng hòa; French: Armée de la république du Viêt Nam) were the ground forces of the South Vietnamese military from its inception in 1955 to the Fall of Saigon in April 1975. It is estimated to have suffered 1,394,000 casualties (killed and wounded) during the Vietnam War.The ARVN began as a postcolonial army that was trained by and closely affiliated with the United States and had engaged in conflict since its inception. Several changes occurred throughout its lifetime, initially from a 'blocking-force' to a more modern conventional force using helicopter deployment in combat. During the American intervention, the ARVN was reduced to playing a defensive role with an incomplete modernisation, and transformed again following Vietnamization, it was upgeared, expanded, and reconstructed to fulfill the role of the departing American forces. By 1974, it had become much more effective with foremost counterinsurgency expert and Nixon adviser Robert Thompson noting that Regular Forces were very well-trained and second only to the American and Israeli forces in the Free World and with General Creighton Abrams remarking that 70% of units were on par with the US Army. However, the withdrawal of American forces by Vietnamization meant the armed forces could not effectively fulfill all of the aims of the program and had become completely dependent on U.S. equipment since it was meant to fulfill the departing role of the United States.At the ARVN's peak, an estimated 1 in 9 citizens of South Vietnam were enlisted, and it had become the fourth-largest army in the world composed of Regular Forces and the more voluntary Regional and Village-level militias.Unique in serving a dual military-civilian administrative purpose, in direct competition with the Viet Cong, the ARVN had also become a component of political power and suffered from continual issues of political loyalty appointments, corruption in leadership, factional infighting, and occasional open internal conflict.After the fall of Saigon to North Vietnam's People's Army of Vietnam (PAVN), the ARVN was dissolved. While some high-ranking officers had fled the country to the United States or elsewhere, thousands of former ARVN officers were sent to re-education camps by the communist government of the unified Socialist Republic of Vietnam. Five ARVN generals committed suicide to avoid capture by the PAVN/VC.