
Cambodia was a French colony for almost hundred years until it gained its independence in 1953. The king of Cambodia, Norodom Sihanouk, held all power until 1970 when he was removed from power in a bloodless coup d'etat by right wing forces led by Lon Nol. Sihanouk had tried to remain neutral during the Vietnam War. He refused to accept economic aid from The United States of America and broke off diplomatic relations with the USA in 1965.
A bloody civil war broke out between the Cambodian right wing government and the Cambodian communist guerrillas, better known as the Khmer Rouge (Red Khmers). Lon Nol's government received economic and military aid from the USA and soon drifted into the Vietnam war. The USA bombed the Cambodian countryside in an attempt to destroy the North Vietnamese communist guerrillas.
The Khmer Rouge led by Pol Pot captured the capital Phnom Penh and all of Cambodia in 1975. After capturing the capital, they forced its population to move to the countryside and started a communist revolution.
It is estimated that 1–1.5 million Cambodians lost their lives during the Pol Pot era.
The Pol Pot regime abolished money, shattered families, destroyed the school system, and prohibited all religious practices. Supporters of the previous regime were executed along with large numbers of the educated members of society. Many Cambodians died of hunger, sickness, and forced labour. Many people were tortured and murdered during internal purges in the communist party. It is estimated that 1–1.5 million Cambodians lost their lives during the Pol Pot era.
In 1979, the Vietnamese army occupied Cambodia and drove the Khmer Rouge to exile near the Thai border. Vietnam installed a friendly government in Phnom Penh. Members of the new government included former Khmer Rouge members that had fled Pol Pot's internal purges to Vietnam and opponents of the former Khmer Rouge government. A civil war broke out between the Phnom Penh government and the Khmer Rouge that were located near the Thai border. The Khmer Rouge represented Cambodia during the 1980s in the United Nations. At the same time, the Cambodian government didn't receive economic aid from the United Nations or from the Western countries. Consequently the reconstruction of Cambodia was slow and the economic situation in the country was severe.
In 1990, the Cold war came to an end. In the previous year, the Vietnamese had removed their troops from Cambodia. The USA wanted to reduce the tensions in the area as well and stopped supporting Khmer Rouge's status as representatives of Cambodia in The United Nations.
In 1991, the parties of the civil war signed an agreement with the aid of the UN to end the hostilities in Cambodia. The peace treaty, known as the Paris Peace Accords, gave the UN a large mandate to build peace in Cambodia. The UN was to lead Cambodia to democracy and peace by organizing free and fair democratic elections. In the elections that were held in 1993, more than 90 % of the Cambodians cast their votes. The pro-monarchy party (FUNCINPEC) that won the elections and the party that represented the previous regime (CPP) formed a coalition government.
The relationship between the two parties was characterized by lack of trust: both of the main parties in the government had their own armed forces. It proved impossible to unite them into one national army. The tensions between the parties led to an armed conflict in the streets of Phnom Penh in July 1997. The CPP emerged as the stronger party, and its leader Hun Sen became the dominant figure in Cambodian politics.
Second national elections were held in 1998. The CPP won the elections. The same party was victorious also in the communal elections of 2002.