Four years after the last American official left Saigon, the threats of war rather than the promises of peace preoccupy Hanoi.

It was not to have been this way. Saigon and the Mekong Delta, renowned for rice, fish, fruit and the art of gracious living, were to be the prizes at the end of the war for a reunified Vietnam. The industrialized north and the agricultural south were to balance each other as efficiently and gracefully as the two rice baskets on either end of the shoulder pole carried by Vietnamese peasants: The Vietnamese image for the shape of their country.

It has turned out otherwise. The policies that worked in Hanoi could not be transplanted in the south. The ethnic Chinese -- proportionately greater in number here than in Hanoi -- ran the southern market out of Cholon and they would not accept communism voluntarily. Farmers are withholding their bountiful crops because government prices are far lower than those they can fetch on the private market. The industrial potential of Ho Chi Minh City has not been fully tapped because, among other reasons, the factories are dependent on equipment and parts from the United States, which has forbidden trade with Vietnam.

After an airplane ride from Hanoi, which is trapped in the still heat and humidity of the Red River Delta, Ho Chi Minh City feels fresh, cooled by breezes at dusk and spared the foul noon-time air of the north. The city's markets are still the envy of Hanoi: fruit and vegtables are abundant, synthetic cloth is available by the yard, pottery and glassware are of good quality if expensive. Yet easily one-third of the market stalls are empty. The cache of modern gadgets and luxuries left in 1975 is drying up. Ho Chi Minh City has fewer goods to offer on the surface than a wealthy provincial city in Thailand.

Ho Chi Minh City seems halfway between its old and new self, held back by the problems left from the American presence, by Hanoi's policies and by southern resistance. Yet, during a five-day stay in Ho Chi Minh City, I heard only one official praise it. Everyone else could only see problems.

"The Americans left behind more difficulties than favors," said Le Quang Chinh, the city's deputy mayor and former deputy foreign minister of the Provisional Revolutionary Government of South Vietnam. "They left behind 1 million unemployed or semiemployed. We've found jobs for 250,000 already. There were 100,000 drug addicts and prostitutes . . . Ho Chi Minh City is the only place in the country with these problems," he said.

It is not the wanton hustling city of old but until it becomes a facsimile of Hanoi, it will be viewed warily. "The system must be the same in all cities of Vietnam, not only Ho Chi Minh City and Hanoi. We are making good progress but still we have to be vigilant," said the deputy mayor.

She wore the only gold watch I saw in Hanoi and her traditional dress was fashioned with tailored perfection rare in Vietnam today. The charm and polished beauty of Madame Nguyen Thi Binh is intact.

Gone is the aura of power that capped her image when she traveled from the guerrilla fronts in the south to the Paris peace talks, the striking foreign minister of the Provisional Revolutionary Government of South Vietnam. Today the former voice and symbol of women's liberation in Asia is the minister of secondary education of Vietnam, and like many other former figures of the government of the National Liberation Front, she has status without power.

"I prefer education," said Binh with a hint of chagrin. "Before I became a revolutionary I was a teacher. I think our duty to educate a new generation is a beautiful and important task, especially for a woman."

Victory in the south for Vietnam's Communist Party has brought many changes, but not necessarily the ones many foreigners and Vietnamese themselves had expected. The presence of Binh in Hanoi in a reduced role, rather than in the south helping run her native region, is only one clue to the shattered illusions that lie heavily on Vietnam today.

Women have not taken up important roles in Vietnam's leadership, as Binh suggested they would a decade ago. The south is not integrated. The new kind of revolutionary humanity many thought would emerge after a successful conquest has given way to bureaucratic apparatus. Poverty has overwhelmed Vietnam despite its egalitarian system as it does most Asian developing nations.

Hanoi, too, has slums.

The official American illusions about Vietnam also proved fragile: There were no bloodbaths and the vaunted U.S. goal of containing China by fighting in Indochina has been taken up by the Vietnamese Communists themselves.

Forced to be larger-than-life during the war by both friends and foes, the Vietnamese could never keep up their Third-World superman image. Binh, routinely brought forward to see those journalists allowed to visit Hanoi, showed enthusiasm but embarrassingly little detailed knowledge of education in Vietnam and less about her government's international diplomacy. Her role, it seems, is to explain the government's new vision of women.

"I am very proud of our women's movement," she begins. "In the family, Vietnamese women are good and gentle mothers. In the society, they are also good laborers and workers. They reserve for themselves very little and work for their husbands, their children and their country. Their role in the society has changed since the war, but not in the family. The wife remains the head, the husband the vicehead."

This is a different version than the one of women's equality in all facets of society that she extolled when she represented the Provisional Revolutionary Government.

"During the war," she said in an interview at the aging, austere hotel where I stayed, "women had to learn the skills and the knowledge of science, politics and culture. Now there is less urgency."

Another man who was once a deputy minister in the Provisional Revolutionary Government and who is now posted in Hanoi privately admitted that the south was quite different from the north and voiced a deep longing to return to Ho Chi Minh City. "We are unified, one country. But the food in the south is so much better, the air. The customs are softer, not rigid and conservative like they are here."

The greatest shock to the southerners, he and others said, was the quick unification of Vietnam and the urgent push to make Hanoi the indisputable capital. The American Phoenix program is blamed by the Vietnamese for assassinating nearly three-fourths of the southern Communist cadre and thus making it necessary for early reunification and for the large role northerners play in administrating the south.

"The north is an ordinary communist country. That is the hardest lession for an American," said one Western resident of Hanoi sympathetic to the government. "It is a police state. You need permission to travel anywhere outside the city, everyone spies on each other and it has been this way throughout the war. It is also the one power that defeated the United States."

"The south, no. It is far more complicated," he continued. "In some ways it has to be ruled as a separate country."

In the south, especially, the ghost of the American presence has not been exorcised. As much as American officials had to believe they were defeated by the superior "Prussians of Asia," so the Vietnamese began to see themselves in heroic proportions. But now, with the Americans gone, the Vietnamese are aging Davids without an American Goliath to challenge.

Vuu Hanh, a famour Saigon nationalist writer during the war, one who was jailed regularly, spoke at his Writer's Association headquarters in Ho Chi Minh City with nostalgia about the old days when Saigon was front-page news and the country seemed to be the center of the universe.

"When my daughter was jailed it was international news. The American writers, the television correspondents made it news and my daughter was liberated," he said. When asked if it would be international news if, today, his daughter was thrown in jail, Vuu Hanh laughed and answered: "No, but she wouldn't be put in jail."

Neither Vuu Hanh nor his daughter, Phoung Thao, now an illustrator of children's books, has written critically of the new government, the crime for which they were punished under the old government. He sticks to writing stories about the war, "the source of my inspiration and knowledge," and says he sees no reason to criticize the new leadership.

"In the constitution it says that no one can use his individual liberty to undermine the interests of the nation," he explained.

At the Chi Hao Prison of Ho Chi Minh City, built by the French and still used to hold political prisoners, Luu Xuan Dien was brought out to describe how the ethnic Chinese duped him into working in the illegal refugee traffic and to show that Hanoi was innocent of such traffic and that the ghost of corrupt old Saigon continues to haunt the nation.

The 29-year-old northerner unintentionally explained how his six years in the party and 11 years in the army did not prepare him for the loneliness and disappointment that followed peace. His bleak story gave a glimpse of the miscalculations of Hanoi about the south and its own people.

A veteran of battles in Cambodia and South Vietnam, Dien asked to return to his home in Ha Bac Province in the north after he participated in the final battle for Saigon. "They said, no, I had to stay in Ho Chi Minh City with the security forces. I was allowed three trips home over the next four years. On the first trip, in 1976, I was married," he said.

The eldest son of aging parents, newly married and very homesick, Dien said he again sought a transfer to the north. Refused again, he applied for his wife to join him. "Many men were allowed to go back from my unit but not all. I had to stay in the south because I was an officer," he continued.

His wife's peasant background kept her from joining him. "Only the wives who were educated and had special skills could join their husbands in the south. Mine is a common farmer. She wouldn't be able to add any skills to the city," he said.

As a member of the city's security force, Dien helped register the city businesses and their assets, and he guarded the banks when the citizens were ordered to place their money into government accounts. He became known and in 1979 he was offered a bribe to camouflage a convoy of would-be refugees. He was caught and sentenced to seven years imprisonment.

Dien's explanation for succumbing to temptation was intriguing, since it was told in front of seven officials, as was his entire tale. "Since liberation I did my duties, but I wasn't allowed home when my family needed me. I made little money, not enough to help them and my wife."

A party official interjected: "It was all a matter of money."

Dien answered, yes, that was true. "I know many people are separated from their families. It was common during the war but I thought it would end with peace," he said. "I thought about the money after my wife visited me in May. We don't have very much. I haven't told her about my arrest."

It would be unreasonable to expect the Vietnamese to easily forget the bombs, the napalm, the strategic hamlet program or even the attention they received during the war. But their most sympathetic allies fear the Vietnamese seem stuck in the last dedade, unable to accept the more subtle world of peace.

"For the first time this year there have been editorials admonishing the people not to be pessimistic. The wartime idea of full-steam-ahead confidence isn't working and they may have caught on," said one weel-informed foreign diplomat.

While saying Vietnam is "not the impossible mess it may appear to be," the diplomat, who has lived in Vietnam a number of years, made an obvious but rarely heard point.

"Everything I was told about Vietnam was wrong in some spectacular way. They are not the brilliant strategists nor subtle diplomats," he said. Only the American blunder made them appear to be so. The illusions vanished with the Americans."

Next: The Cambodian Snare