Formation of the National Liberation Front of South Vietnam (NLF) to promote full-scale revolution against the Sài Gòn regime of Ngô Đình Diệm. Washington and Sài Gòn refer to these revolutionaries as the Viet Cong (VC).
April North Vietnam (DRV) imposes universal military conscription and begins sending cadres to the South (RVN)
May 5 U.S. announces an increase in the number of MAAG (Military Assistance Advisory Group) advisors above the Geneva imposed ceiling of 342.
August 9 In Laos, Captain Kong Le leads the 2nd Lao Paratroop Battalion in a coup d’etat against the right wing government of Prince Somsanith and forms a neutralist government of Laos, open to both Royalists and the Pathet Lao (Lao Nation or Homeland) Communist party). The political movement of the Pathet Lao was called first the Lao People’s Party (1955–1972) and later the Lao People’s Revolutionary Party (1972–present). Key Pathet Lao leaders include Prince Souphanouvong, Kaysone Phomvihane, Phoumi Vongvichit, Nouhak Phoumsavanh and Khamtay Siphandone.
August 15 General Phoumi Nosavan demounces Kong Le as a Communist and forms a counter-coup committee (Revolutionary Committee) nominally under Prince Boun Oum in Savannakhét.
August 16 Wishing to end the fighting in Laos, Kong Le hands over power to a neutralist government under Prime Minister Souvanna Phouma.
November 11-12 South Vietnamese paratroopers stage a failed coup d’état against President Ngô Đình Diệm.
December 4 The Soviet Union begins airlifting supplies to Kong Le’s neutralist forces in Vientiane. Thailand, which supplies food and fuel to the city, had previously imposed a blockade on the Laos capital.
December 9 Laos Prime Minister Souvanna Phouma hands power to the military and leaves Vientiane (Laos) for Cambodia.
December 13 Backed by the CIA, Phoumi Nosavan’s Royal Laotian Army begin their assault on the capital.
December 16 Phoumi’s royalist troops retake Vientiane. Kong Le retreats north towards the Plaine des Jarres (Plain of Jars).
December 20 National Liberation Front (NLF) of South Vietnam forms with the aim of overthrowing Diệm’s government and reunifying the country. The NLF (to the US and Sài Gòn government, the Viet Cong or VC) is a coalition of diverse groups, among them Vietnamese communists, Cao Dai, ethnic Cambodians, and intellectuals opposed to the GVN. They had come together for the purpose of reunification, reform of government, and elimination of foreign controls. In Sài Gòn former government officials and other professionals in opposition to the Diệm government are arrested.
December 31 US military personnel in South Vietnam: Approximately 900.