There were repeated attempts from 1954 onward to force the North Vietnamese out of Laos, but regardless of any agreements or concessions, Hanoi had no intention of withdrawing from the country or abandoning its Laotian communist allies.

[20] On 21 March 1946, Souphanouvong and his largely Vietnamese force fought the French Union troops at Savannakhet, to no avail; the attackers mustered paratroopers, artillery, armored cars, and Spitfire fighter-bombers.

[33] On 23 December 1950, the Pentalateral Mutual Defense Assistance Pact was signed by the United States, France, Vietnam, Cambodia, and Laos; it was a tool to transfer American military aid to the French war effort in Indochina.

The North Vietnamese invaders succeeded in conquering the border provinces of Phongsali and Xam Neua, which were adjacent to northern Vietnam and on the northeastern verge of the Plain of Jars.

These were diversions[20] to the famous Battle of Dien Bien Phu, which took place from March through May 1954 within ten kilometers of the Lao border, on the lines of communication into the Plain of Jars.

U.S. President Dwight D. Eisenhower's solution was to establish the Programs Evaluation Office (PEO) in December, 1955, staffed by American civilians with prior military experience and headed up by retired Brigadier General Rothwell Brown.

[52] On 9 August 1960, Captain Kong Le and his Special Forces-trained Neutralist paratrooper battalion were able to seize control of the administrative capital of Vientiane in a virtually bloodless coup,[57] while Prime Minister Tiao Samsanith, government officials, and military leaders met in Luang Prabang.

[61] Alongside its covert Kaw Taw operation, immediately after Kong Le's coup the government of Thailand began an embargo via land blockade, cutting off the main source of imported goods for Vientiane.

Their withdrawal was covered by artillery fire from the PAVN 105 mm howitzers rushed in from Hanoi, and supported by Soviet airdrops of crucial supplies of rations, munitions, and radios.

[69] An inter-agency task force set up by the incoming Kennedy administration in early February undertook a two-month study of possible American responses to the Laotian civil war.

Paramilitary trainers would train guerrilla units, with resupply coming via airdrops, and specialized short takeoff and landing aircraft using makeshift dirt airstrips.

On 19 May, the United States Air Force began flying mid and low-level missions over the renewed fighting, under the code name Yankee Team.

[80] They also began reconnaissance missions over the Laotian panhandle to obtain target information on men and material being moved into South Vietnam over the Ho Chi Minh Trail.

[82] On 3 April, the U.S. began Operation Steel Tiger over the Laotian panhandle and the Vietnamese DMZ to locate and destroy enemy forces and materiel being moved southward at night on the Ho Chi Minh Trail into South Vietnam.

This seemed to be irrational thinking to many Americans flying these combat missions for these trucks could have been destroyed en masse before, during, or after their unloading from the freighters that had hauled them to North Vietnam if bombing of Haiphong had been permitted.

[citation needed] Laotian tribal irregulars were operating out of Nam Bac, under CIA direction from Luang Prabang, some 60 miles south of the guerrilla base.

Despite the poor training of the Lao soldiers, some of whom had never fired a weapon, these raw new units were moved northward out of Luang Prabang over a several month period to garrison Nam Bac.

Its goals were to cross into Laos toward the city of Tchepone and cut the Ho Chi Minh Trail, hopefully thwarting a planned North Vietnamese offensive.

Souphanouvong, by contrast, was confident and a master political tactician, and had behind him the disciplined cadres of the communist party and the Pathēt Lao forces and the North Vietnamese army.

But press censorship was introduced in the name of "national unity", making it more difficult for non-communist forces to organise politically in response to the creeping Pathēt Lao takeover.

[citation needed] In the city of Savannakhet, border at Mekong River on opposite side Thailand, several Pathet Laos underground organization members launched smaller uprising revolution against current Laotian right-wing leaders.

Prime Minister Souvanna Phouma, dreading further conflict and apparently trusting Souphanouvong's promises of a moderate policy, gave instructions that the Pathēt Lao were not to be resisted, and the U.S. began to withdraw its diplomatic personnel.

Most Western countries, including prominent long-time ally United States, closed their embassies either shortly before or after the rise of the establishment of Laos PDR claimed the new communist authoritarian government hasn't implement a new Constitution and the affliction of ideological deterioration.

[96] In September 1975, during an interview, Prime Minister Phouma stated his wish to stay in office until 1976 so he could plan the major steps needed for the long-term reunification process, and to ensure the Pathet Lao did not take away some of the political powers of the monarchy.

Phouma hoped that the 1976 election will select a new head of state from the majority faction, assumed to be the Pathet Lao, who will create the new nonprovisional Vientiane government, with the promise of retaining some liberties and potentially be more open diplomatically with non-communist Thailand.

[98] A few royal family members, including a Prince, crossed the Mekong River and evacuated to Thailand a few days before the establishment of the Laos PDR, fearing societal upheaval and persecution.

The vast majority of the royal family of Laos, including the deposed king, were also sent to the "re-education camps", where most eventually died from starvation and hard labor during the totalitarian period of the 1980s.

In proportional terms, Laos experienced the largest refugee flight of the Indochinese nations, with a full 10% of the population – 300,000 people out of a total of 3 million – crossing the border into Thailand.

[citation needed] In 2004, following several years of pressure from a coalition of U.S. human rights activists,[119] the U.S. government reversed its policy of denying immigration to Hmong who had fled Laos in the 1990s for refugee camps in Thailand.

A memorial to American and Hmong contributions to U.S. air and ground combat efforts during the conflict was established by the Lao Veterans of America, the Center for Public Policy Analysis, in cooperation with the U.S. Congress and others.