Laos Laos formed, together with present-day Vietnam and Cambodia, the French colony Indochine in the first half of the 20th Century. In October 1953, the Franco-Lao Treaty of Amity and Association transferred power to the independent Royal Lao Government, which did not include any representatives from the anti-colonial armed nationalist movement, Lao Issara.

The early resistance against the French consisted in Laos primarily of local ethnic rebellions or actions organized by the Vietnamese-dominated Indochinese Communist Party (ICP). During 1945, when Japan briefly occupied Indochina for five months, different Laotian nationalist movements with links to ICP, Japanese, Thai, "Free French", and American forces united into the Lao Issara (Free Laos Movement, in 1950 renamed the Neo Lao Issara; the Free Lao Front) and proclaimed independence on 12 October 1945. France re-established control over Laos in the following year, but the Lao Issara in close military co-operation with the Vietnamese Viet Minh and Cambodian Khmer Issarak continued the extra-state conflict until independence.

A left-wing faction of the Lao Issara, the Pathet Lao, continued to have close contacts with the North Vietnamese forces as intra-state conflict erupted in 1959-61 and 1963-73. The conflict became part of the regional war in Indochina at the time, and the government was supported by troops from Thailand, South Vietnam, and the USA. The conflict ended with the creation of a coalition government but the Pathet Lao leadership abolished the monarchy and proclaimed a one-party communist state in December 1975. The communist takeover was followed by a mass exodus of refugees into Thailand, primarily royalists and ethnic minorities such as the Hmong tribe. Many of these had historically been employed in the French and American forces, and many left behind were put in so-called "re-education" camps by the new government.

While the government launched massive repression against many civilians, some refugees organised into right-wing insurgency movements that launched occasional attacks on the government along the Lao-Thai border and in a mountainous area north of the capital Vientiane. These attacks eventually escalated to a brief period of active intra-state conflict in 1989-90.

In 1986-1988, Laos and Thailand fought an inter-state conflict over disputed border areas after disagreement on the interpretation of a 1907 French-Thai demarcation Treaty.

The Laos government continued to employ one-sided violence against ethnic minorities in its campaigns against perceived resistance to its rule, as the survivors fled into refugee camps in Thailand.

Since 1946, Laos has experienced the extra-state, inter-state, intra-state and one-sided categories of UCDP organised violence.