THE SECOND MONTH I was in Vietnam I took a transport plane from Bien Hoa up to Cam Ranh Bay to conduct some business for my company. I eventually had to go to Nha Trang and Cam Ranh was the staging point for traffic flying north.

Looking down as we made our approach I saw a hugh sprawl of buildings--arranged by some methodical mind that must have paid meticulous attention to right angles. Some 40,000 men were stationed at Cam Ranh in 1968 and the base had every sort of facility: stores, clubs, hospitals, restaurants, steam-baths, bars, barracks, airfields, laundries and row upon row of little air-conditioned hootches for Air Force pilots.

Planes landed at Cam Ranh every six minutes; ships unloaded millions of tons of supplies there monthly; hundreds of thousands of soldiers flew into the base to be reassigned to the northern parts of South Vietnam. It was incredible to me then that three years before there had been nothing there but white sand and the startling blue water of the South China Sea.

Last year I talked with a reporter who was in Cam Ranh about six months age. Sand drafts are covering the roads now, packs of wild dogs roam around the post and the 5000 beds of the 12th Evac Hospital are all empty. The street lights still turn on automatically every evening.

It is difficult to imagine Vietnam without Americans. The war and the Country became real to me the moment I arrived and saw Americans everywhere.

Vietnam stopped when I left in 1970. A week later I was skiing at Lake Tahoe, tan in the middle of February, and already my mind could not embrace the idea that the war still went on.

VIETNAM FOR ME had not been an historical lesson, or an example of American imperialism, of even a catastrophic event. It had been an intensely personal and over-whelmingly subjective experience which intruded on the me and was suddenly over--with no apparent meaning or logic to it.

I did not know what to make of those one and a half years and so I froze the images I had stored up and shoved them to the back of my mind. They meant nothing to anyone and were irrelevant entering Harvard.

But my mind would not allow me to play that kind of game for long, and neither would the people around me. I was forced, by myself and others, to try to arrive at the meaning of the experience.

I immediately had to face the question of guilt. I might have said that I was a victim--that Vietnam happened to me rather than the opposite--but them the question became. "Did you never perform an affirmative act that contributed to the suffering of the Vietnamese?" And I, and all the others who did not go to Canada, must answer yes.

So for me there is a studied ambivalence in all my attempts to come to grips with the war. And in that respect I feel kinship with the Frances FitzGerald and admiration for her attempt to bridge the gap between personal experience and historical resolution in Fire in the Lake.

FitzGerald went to Vietnam as something I was not. She was a trained journalist, to whom history was important and she saw more than I or most Americans the abyss between what was told and what was happening. She felt early a responsibility to describe the illegitimacy of the American intervention.

After a time she felt that to merely report about the war did not resolve the dilemma of Vietnam and she, unlike most of us there, could not shove those questions aside.

FitzGerald became dissatisfied with the role prescribed for her. She was like all of us in one way: confined by her white skin and "round eyes" to certain areas at certain times of day. All Americans found out quickly that going after the truth about Vietnam was the hardest thing of all.

How could we seriously attempt to analyze a country that, for all intents and purposes, changed hands every 12 hours? By day Americans could, for the most part, go where they wished; by night we huddled inside thousands of perimeters all over the country, straining to see the enemy out there who could suddenly do us great damage and, just as suddenly, disappear.