Sihanouk on Cambodia's anguish; War and Hope: The Case for Cambodia, by Prince Norodom Sihanouk. New York: Pantheon, $10.95.

This is far from the final word on Cambodia. Indeed it is in many ways disappointing. Rambling, illogical, and overly wordy in places, Prince Norodom Sihanouk tells us less than we would like to know about the time he spent working with the Cambodian communists and then serving as their captive. Perhaps this reflects Sihanouk's isolation during the war years and the fact that the Prince was prevented from learning all he would have liked.

At the end of this book, we are still left wondering what it was that drove the Khmer Rouge leaders to destroy their own nation, emptying the cities and executing hundreds of thousands of their compatriots.

When it comes to analyzing Vietnam's motives for invading Cambodia and to relating the conversations Sinhanouk had with Vietnamese and Chinese leaders, the Prince is more astute. He reveals the efforts made by China's then-Premier Zhou Enlai in 1970 to persuade him not to break his unhappy alliance with the Khmers rouges.

According to Sihanouk, four persons were largely responsible for Cambodia's reign of terror: then-Premier Pol Pot, Foreign Minister Ieng Sary, and the wives of the two. Without providing much supporting evidence, the Prince claims Hitler was the hero of Pol Pot and Ieng Sary. Sihanouk describes the Khmer Rouge soldiers who served under them as "addicted to torture."

But in the end Sihanouk seems as baffled as everyone else over the cruelty of the Khmers Rouges. He contends that the Vietnamese Army treated the Cambodian people much better in the early 1970s than did the Khmers Rouges. Sihanouk also argues that the Khmers Rouges helped bring on the Vietnamese invasion of their country by constant provocations, including claims on Vietnamese territory which had once been Cambodian.

Prince Sihanouk's solution for Cambodia consists of an international conference, internationally organized military forces to guarantee a cease-fire and then oversee legislative elections, and Swiss-style neutrality that would make Cambodia "truly neutral, not merely nonaligned."

Although he was once highly critical of the United States, the Prince considers the position that was taken by the Carter administration on Cambodia to have been laudable and supportive of Sihanouk's proposed solution.

One of his main points in that Cambodia has no choice but to seek accommodation with Vietnam. The Khmer Rouge leaders, he says, were totally unrealistic in provoking confrontation with the much more powerful Vietnamese. Consider, to start with, that Vietnam has about ten times the population of Cambodia.

Sihanouk lists numerous Vietnamese actions, from 1940 to 1970, which he says caused him "personal bitterness" toward Hanoi. But he explains that his decision to help the Vietnamese communists during the Vietnam war was designed to put Vietnam in Cambodia's debt "in such a way that it would never dare to raise a hand . . . against our country and our people, its benefactors. To do otherwise would bring them total dishonor."

Sihanouk contends that only he is capable of negotiating with the Vietnamese on behalf of Cambodia and that the Vietnamese "will not refuse to negotiate" with him. But elsewhere in the book he contradicts this contention, when he asserts that "Hanoi is afraid Norodom Sihanouk might be restored to power." He also states that Vietnam's major supporter, the Soviet Union, has a "distrust, if not to say visceral hatred" of him because of his friendship with the Chinese.

Even if the Vietnamese were to lean toward restoring Sihanouk as a compromise solution, he says, the Soviet "would never give them the green light."

The Sihanouk solution seems imminently reasonable. But neither the Chinese nor the Soviets, not to speak of the Soviets' Vie tnamese allies, are buying it.