In stark contrast to neighboring Cochinchina and to the other Vietnamese-populated territories of Indochina, Cambodia was relatively quiescent politically during the first four decades of the twentieth century. The carefully maintained fiction of royal rule was probably the major factor. Khmer villagers, long inured to abuses of power, believed that as long as a monarch occupied the throne "all was right with the world." Low literacy rates, which the French were extremely reluctant to improve, also insulated the great majority of the population from the nationalist currents that were sweeping other parts of Southeast Asia.

Nevertheless, national consciousness was emerging among the handful of educated Khmer who composed the urban-based elite. Restoration of the monuments at Angkor, which the historian David P. Chandler suggests was France's most valuable legacy to the colony, awakened Cambodians' pride in their culture and in their past achievements. Many of the new elite were graduates of the Lycée Sisowath in Phnom Penh, where resentment of the favored treatment given Vietnamese students resulted in a petition to King Monivong during the 1930s. Significantly, the most articulate of the early nationalists, were Khmer Krom (see Appendix B)--members of the Cambodian minority who lived in Cochinchina. In 1936 Son Ngoc Thanh and another Khmer Krom named Pach Chhoeun, began publishing Nagaravatta (Angkor Wat), the first Khmerlanguage newspaper. In its editorials, Nagaravatta mildly condemned French colonial policies, the prevalence of usury in the rural areas, foreign domination of the economy, and the lack of opportunities for educated Khmer. Much of the paper's journalistic wrath was directed toward the Vietnamese for their past exploitation of Cambodia and for their contemporary monopolization of civil service and of professional positions.

The Khmer were fortunate in escaping the suffering endured by most other Southeast Asian peoples during World War II. After the establishment of the Vichy regime in France in 1940, Japanese forces moved into Vietnam and displaced French authority. In mid1941 , they entered Cambodia but allowed Vichy French colonial officials to remain at their administrative posts. The pro-Japanese regime in Thailand, headed by Prime Minister Field Marshal Luang Plaek Phibunsonggram, requested assurances from the Vicky regime that, in the event of an interruption of French sovereignty, Cambodian and Laotian territories formerly belong to Thailand would be returned to Bangkoh's authority. The request was rejected. In January 1941, a Thai force invaded Cambodia. The land fighting was indecisive, but the Vichy French defeated the Thai navy in an engagement in the Gulf of Thailand (see Japanese Occupation, 1941-45, ch. 5). At this point, Tokyo intervened and compelled the French authorities to agree to a treaty ceding the province of Batdambang and part of the province of Siemreab to Thailand in exchange for a small compensation. The Cambodians were allowed to retain Angkor. Thai aggression, however, had minimal impact on the lives of most Cambodians outside the northwestern region.

King Monivong died in April 1941. Although his son, Prince Monireth, had been considered the heir apparent, the French chose instead Norodom Sihanouk, the great grandson of King Norodom. Sihanouk was an ideal candidate from their point of view because of his youth (he was nineteen years old), his lack of experience, and his pliability.

Japanese calls of "Asia for the Asiatics" found a receptive audience among Cambodian nationalists, although Tokyo's policy in Indochina was to leave the colonial government nominally in charge. When a prominent, politically active Buddhist monk, Hem Chieu, was arrested and unceremoniously defrocked by the French authorities in July 1942, the editors of Nagaravatta led a demonstration demanding his release. They as well as other nationalists apparently overestimated the Japanese willingness to back them, for the Vichy authorities quickly arrested the demonstrators and gave Pach Chhoeun, one of the Nagaravatta editors, a life sentence (see Japanese Occupation, 1941-45, ch. 5). The other editor, Son Ngoc Thanh, escaped from Phnom Penh and turned up the following year in Tokyo.

In a desperate effort to enlist local support in the final months of the war, the Japanese dissolved the French colonial administration on March 9, 1945, and urged Cambodia to declare its independence within the Greater East Asia Co-Prosperity Sphere. Four days later, King Sihanouk decreed an independent Kampuchea (the original Khmer pronunciation of Cambodia). Son Ngoc Thanh returned from Tokyo in May, and he was appointed foreign minister. On August 15, 1945, the day Japan surrendered, a new government was established with Son Ngoc Thanh acting as prime minister. When an Allied force occupied Phnom Penh in October, Thanh was arrested for collaboration with the Japanese and was sent into exile in France to remain under house arrest. Some of his supporters went to northwestern Cambodia, then still under Thai control, where they banded together as one faction in the Khmer Issarak (see Appendix B) movement, originally formed with Thai encouragement in the 1940s.

Data as of December 1987