After the 1954 Geneva Accords, which the US did not sign, strengthening the anti-communist governments of Indochina became a priority for President Dwight Eisenhower's administration. For the US, Laos, not South Vietnam, was the key to Indochina; their policies were motivated by the fear of the Domino Effect that could follow in Southeast Asia were Laos to turn communist.

As of 1955, the US was bankrolling the Royal Lao Army, countering the Viet Minh, which was financing the Pathet Lao's army. For the next eight years, the US spent more on foreign aid to Laos per capita than it did on any other Southeast Asian country, including South Vietnam.

When the elections of May 58 gave leftist candidates 21 seats in the National Assembly, the United States got worried and engineered the collapse of the government led by the moderate Prince Souvannaphouma (half-brother of Souphanouvong) and the arrest of Pathet Lao leaders, including Souphanouvong. Power in Vientiane had shifted to the American Embassy, and civil war in Laos seemed inevitable.

With help from the US-backed Committee for the Defence of National Interests (CDNI), General Phoumi staged a coup in December, and when new elections were held, a rigged ballot left the leftists without a seat. As a result, national support for the Pathet Lao increased, and by 1960, roughly twenty percent of the population was no longer under government control. Meanwhile, all fifteen Pathet Lao prisoners, including Souphanouvong, escaped from jail.