The only detailed evidence for the trip comes from the Livre noir. Pol Pot contended that he was summoned north to be told to stop fighting. This does not ring true, but his account suggests that he was more forthright with the Vietnamese this time than he had been in 1965 and that some of his demands—which may have been for more military assistance and increased autonomy—angered his counterparts in Hanoi. The Vietnamese would have rejected both requests, although their failure to imagine an alternative to Sihanouk, now on the ropes, forced them to remain allied with Sar’s unsatisfactory party. The Livre noir asserts that the Vietnamese in Cambodia “had taken refuge in areas controlled by the Communist party of Kampuchea,” a reversal of what Sar and Ieng Sary had done in 1963; this suggests that the Vietnamese needed Cambodian protection more than the Cambodians needed patronage from Hanoi. Although these attitudes were common currency among party faithful by 1978, they had not come into the open at the time of Sar’s visit to Hanoi. Had Sar made such demands in 1969, even in the heat of the moment, he would have drawn the angry response he said he drew in the Livre noir Had he made them part of a coherent, independent policy, it is likely that the Vietnamese would have replaced him as secretary of the party. At the same time, it is possible that even a polite request by him for assistance would have been dismissed out of hand. In other words, although it is likely that the Livre noir narrative is an accurate description of Sar’s psychological state in 1978, and perhaps of his anger in 1969-1970, his conduct and statements until about 1972 cannot be construed as independent or anti-Vietnamese. Indeed, if relations between Cambodia and Vietnam were as poor as the Livre noir suggests, it is doubtful that Saloth Sar would have risked a trip to Hanoi or that he would have lingered there as he did for several months. What Sar probably found offensive about his visit was that the Vietnamese, whose thoughts were elsewhere, once again failed to come to grips with his importance, the sufferings of his followers, or the uniqueness of the Cambodian revolution.37

Meanwhile, events were moving rapidly in Phnom Penh. In January 1970 Sihanouk left for his annual rest cure in France, unintentionally beginning a life of exile that was to last several years. Before leaving, he had been psychologically bruised by encounters with the hostile National Assembly. Partly to regain control and partly because he was genuinely frightened of Vietnamese incursions, he asked Lon Nol to increase pressure on Communist forces. While the prince was overseas, supplies to the Vietnamese forces in Cambodia were cut off, and government-sponsored riots damaged the diplomatic missions of Vietnamese Communists in Phnom Penh.38