After Lon Nol came to power in a military coup in 1970, war and disturbance, including massacre by the Pol Pot regime and the invasion by Vietnam, continued for more than two decades in Cambodia. The Paris Peace Accord was signed under the guidance of the United Nations in 1991. In 1993, democratic elections were held and a new government was established. Subsequently, a new democratic constitution was enacted, and the country was reborn as the Kingdom of Cambodia.
The United Nations established the United Nations Transitional Authority in Cambodia (UNTAC) in 1992 to undertake various activities, such as maintaining a ceasefire, disarmament, observing elections, support for the return of refugees, as well as administrative management.