By this time, Sihanouk had hardly any influential friends. A Western diplomat remarked that in his career he had never seen such a wide gap between a ruler and an indigenous middle class. To the Red Khmer, the prince had become indistinguishable from Lon Nol as their “Number One Enemy.” Sihanouk’s campaigns against radical students, his violent response to the Samlaut uprising, and his diplomatic rapprochement with the United States made the possibility of a united front, in spite of Vietnamese encouragement, remote. In the meantime, elite support for the prince eroded further as Sino-Cambodian businessmen found themselves blocked from participating in the economic boom affecting much of Southeast Asia. Cambodian bureaucrats and army officers felt the pinch of declining revenues. Many of their children, unhappy at Sihanouk’s failure to deliver justice or employment, drifted toward the left. Others, less politicized, grew weary of his monologues, his narcissism, and his unsavory entourage.

In the middle of 1969 Sihanouk renewed diplomatic relations with the United States, alienating what little radical support he had retained. He may have hoped that the Americans would provide military aid to turn his army into an effective force and prevent the Vietnamese Communists from encroaching further on Cambodian territory. No such aid was forthcoming. Instead, the new American president, Richard Nixon, had another game plan for the Khmer.

Nixon was committed to withdrawing American troops from Vietnam. To protect this operation he agreed to proposals from his military commanders in Saigon that U.S. B-52 aircraft commence bombing Vietnamese Communist bases and troop concentrations inside Cambodia. News of this bombing, which began in March 1969, was kept from the American people. Whether Sihanouk had authorized it or accepted it as a fait accompli remains unclear. In any case, it continued for more than a year, with over three thousand raids against Cambodian targets. In the eastern part of the country the bombing turned many young men and women into revolutionaries. Between 1968 and 1970, estimates of guerrillas under arms more than doubled; by 1970, some four thousand Cambodians were confronting Phnom Penh’s better-armed, but not especially competent, army. Another effect was that Vietnamese forces moved deeper into Cambodia to avoid the bombing. Step by step, Cambodia was entering the Indochina war.

Prime Minister Lon Nol and his ambitious deputy, Prince Sisowath Sirik Matak, supported the bombing campaign. Both men wanted Vietnamese forces to leave Cambodia. In public, Sihanouk and the Vietnamese maintained the charade that the bases were not there. In private they pretended that their alliance remained in force, even as Sihanouk’s armed forces, under Lon Nol, attacked Red Khmer and, through them, the Vietnamese. In some areas by early 1970, Red Khmer guerrillas under Vietnamese command were fighting Lon Nol’s forces. The United States and North Vietnam, in effect, were waging war on Cambodian soil. Sihanouk’s neutralist policy was in tatters. The game he had played since 1955 was lost. Sirik Matak and Lon Nol began plotting to overthrow him.35