How US policymakers in the '40s set the stage for Vietnam; Why Vietnam? Prelude to America's Albatross, by Archimedes L. A. Patti. Berkeley: University of California Press. $19.95

At a time when there is a tendency to revert to simplistic thinking about Vietnam, this book serves a useful purpose. Archimedes L. A. Patti reminds us of the illusions that helped bring the United States into Vietnam on the side of the French after World War II. He supports the view, not original with him, of course, that Ho Chi Minh was more of a nationalist than a Communist. Ho, he argues, was willing, early on at least, to develop a longterm, cooperative relationship with the United States.

If Ho Chi Minh's Viet Minh revolutionary movement had half the popular support which Patti argues that it had, it is little wonder that the French and later the Americans had such a terrible time of it in Vietnam.

This is not the first time that a Westerner has attempted to give us a portrait of Ho Chi Minh. Books about the wily Vietnamese leader by David Halberstam and Jean Lacouture provide more detail than Patti's history does. But Patti adds to the picture by describing the overtures Ho made to the US, sometimes by way of Patti himself, before it came to war.

Ho knew of the American Declaration of Independence and slipped a few lines from it into his own revolutionaries' declaration of independence. He knew of President Franklin Roosevelt's commitment to the principle of self-determination for colonial peoples. But he was to be disappointed. Fearful of the Soviets and eager to make France part of the US alliance with Western Europe, the Americans ended up helping the French to reconquer Vietnam.

Aside from Patti and a few others, most Americans never really knew whom they were up against, at least at the beginning of the Vietnam conflict. One might argue that Patti's portrait of Ho Chi Minh is overly generous, but it is clear that Ho was more complex a figure than many of the black-and- white images of Vietnam which are presented by both the American left and right would allow. This is helpful at a time when films like "The Deerhunter" and "Apocalypse Now" depict the Vietnamese -- not just the Vietnamese communists but all Vietnamese -- as inhuman stick figures. In those films, the Vietnamese provide little more than a backdrop for the agony of Americans.

Patti led a team from the Office of Strategic Services, the precursor of the US Central Intelligence Agency, into Hanoi at the end of World War II to help arrange the Japanese surrender and free Allied prisoners. It was a time, almost forgotten now, when the Americans sought and obtained the cooperation of Ho Chi Minh's Viet Minh against the Japanese.

According to Patti, Ho was desperately trying to align his newborn nation with the West and wanted to put to rest French charges that the Viet Minh was a tool of Moscow. Ho and his colleagues were singularly nationalistic, Patti asserts, and did not commit themselves to Soviet and Chinese support until 1950. With American support, the author argues, Ho might have adopted some form of neutrality.

But Patti writes that most officials in Washington who had anything to do with Asia were obsessed with a stereotype of monolithic communism and never made an effort to probe deeply into the nature of Ho Chi Minh or his independence movement. Washington officials assumed that the emperor Bao Dai had a strong following. He did not. But worse than their ignorance, perhaps, was the ambivalence of US officials. They did not know what they wanted in Indochina. This made them an easy mark for the French, who, at the outset at least, did know what they wanted.

Simply by threatening to pull out of Indochina, the French were able to win concessions and assistance from the Americans, Patti says. But long after the French themselves had given up hope for a military victory in Vietnam, American military advisers in Saigon continued to believe in such a victory.

Patti asserts that the US, in the early stages of the Vietnam conflict, "merely danced to the Soviet tune, reacting to each 'Communist threat' but seldom from a position of strength based on preconceived and firm plans." To a certain degree, he argues, this is still the way of American foreign policy.

"From fear, indecision, and expediency we have been vulnerable to blackmail from both ally and enemy," Patti declares.

This is not light reading. Patti has a compulsion to tell everything. The book is loaded with military acronyms. Colonel Patti might have done better to have shortened his tale.