He knew they were doomed when he saw the ships.

They had left their secret base in the mountains, boarded their unmarked planes amid intense emotion, and once again taken off on a flight to an unknown destination -- south along the Pacific Ocean, away from Guatemala, away from Cuba, then east across Nicaragua, over the capital of Managua, and on to the Atlantic Ocean.

Below, in the center of a cluster of small houses standing on the red earth, they caught a glimpse of a long pier with railroad tracks going out into a harbor.They had arrived at the last secret base, what they knew only as "Trampoline," but actually Puerto Cabezas, Nicaragua, sometimes called (and appropriately, as it turned out) "Bragman's Bluff."

They were confident of victory. But the sight of those hulking old merchant ships brought a chill of doubt. That was not what they had expected; that was not the way the Americans had done it in the newsreels they remembered from World War II.

"The feeling of defeat was when I went to the dock to see the Houston crowded with the two battalions that I took to Playa Larga," Erneido Oliva, second in command of the invasion force, remembers now, long after that last battle and his nearly two years in Cuban prisons. "I felt the situation was really terrible -- the lack of air defenses that we had, the landing craft they gave us. Instead of the LSTs we expected, we had those small open boats with outboard motors. What came to my mind was this: My background as a military man told me we could not make a conventional assault landing that way, but if I, as an individual, said 'No, I won't go,' I would be called by my friends a traitor, a coward. So there was that macho feeling I had that day. And so I went."

They said their farewells to their American advisers, and saw that some had tears in their eyes.They watched as Luis Somoza, then dictator of Nicaragua, come to the docks, surrounded by gunmen, waved, said, "Bring me a couple of hairs from Castro's beard," clenched his fist, turned and walked away. They boarded their merchant ships and headed slowly out to sea for their final rendezvous at the Bay of Pigs.

It was 20 years ago today that they landed at the Bay of Pigs, a name that since has become synonymous the world over with disaster. Seen from the vantage point of a generation later, it would seem that what happened that day on the beaches of Cuba deserves little more than a footnote in history. It was a small operation -- 1,500 men set ashore and swiftly defeated in the salt marshes of the Zapata Swamps. There have been many other bungled, poorly planned military adventures since the Light Brigade plunged into oblivion at Balaklava. The world did not go to war because of that Cuban invasion; history assigned its major credit lines to other events.

But I will argue, with admittedly considerable personal involvement, that the Bay of Pigs was a seminal event of the last two decades -- an episode that touched and affected many critical aspects of American life over this now 20-year span. It was not the cause of a host of problems that followed in its wake, but it was symptomatic of them. And the kinds of questions it raised are with us yet -- questions about the implementation of American force, about the nature of communism and how we choose to deal with it, about the role of the CIA and secret operations, about the climate of doubt created by the conspiracy theories linking the Cubans to the assassination of John F. Kennedy and the now-acknowledged American plots to kill Fidel Castro.

The Bay of Pigs set in motion a chain that stretched, down the years, from crisis to crisis: from defeat on the beaches to the Cuban missile crisis a year later; from failure of American equipped and trained clandestine forces to creation of the Green Berets; from dispatching the Marines and paratroopers into Santo Domingo to stop "Castro-inspired communists" to the increasing flow of U.S. men and arms into Saigon; from covert operatives involved from the beginning with he Bay of Pigs invasion to the arrest of some of the same people at the Watergate break-in more than a decade later. And to everyone it touched it remains a vivid, and often painful memory.

Myself included.

I still recall that eerie feeling while traveling through the Sierra Madre Mountains of Guatemala in the summer of 1963. I was with one of the leaders of the Cuban Brigade 2506 that landed at the Bay of Pigs, on a year's leave of absence from my paper to write a book about the invasion. We were searching for "Base Trax" where the brigade was secretly formed and trained for its invasion.High above the Helvetia coffee plantation, in sight of the volcano, we reached the place where the road should have been. It had vanished. Eventually, from wary Indian peasants in those mountains and later from Cubans who were the last to leave the camp, we learned what happened. Two weeks after the invasion all the camp records were placed in a freshly dug hole and covered with earth by a bulldozer. Soon, Guatemalan soldiers and laborers came. The broke up the camp and carried away every last vestige -- including the cement foundations for the barracks. Then the road itself was bulldozed and covered. The jungle took over. All you could find to connect that territory with the Bay of Pigs was a stray shell casing or a rusting can.

Months later, in Washington, the afternoon of Nov. 22, 1963: I had arranged to meet the same Cuban at the Ebbitt, the small, modest tourist hotel on H Street where the CIA used to place the Cubans. He had just come back from a meeting with high U.S. officials on, as he always said, "the problem of Cuba." There, we learned of the Kennedy assassination. He was told by Robert Kennedy, in a phone conversation, that "one of your guys did it" -- a mistake that grew out of the confusing early reports the attorney general was then receiving about Lee Harvey Oswald's Cuban connections.

Years later in New York, during a conversation with Kennedy, then a senator, he became so emotional about what had happened to the men his brother had sent ashore at the Bay of Pigs that he cried when speaking of the personal commitment he felt toward them.

Even today, there are those I meet from time to time who were there, like my friend Oliva who remembers that first flash of doubt about the condition of the ships that carried him and his troops back to Cuba.

The years have been good to Erneido Oliva, but certainly not uneventful. When we first met he was fresh out fo Cuban prison, the United States of American having just paid the half-million-dollar ransom Castro had placed on his head. He was young, still in his 20s, powerfully built and his dark eyes fairly smoldered with a suppressed intensity. He spoke hardly a word of English.

Oliva was second in command of Brigade 2506, and it's fair to say he emerged from the battle and ensuing 20 months of captivity the most admired of the Cubans on that side. He won't like that description, for Oliva is as modest as he is proud, but one of the reasons for his success in varied activities and his dealings with a wide range of high officials from presidents down has been his reticence. "They know we can keep secrets," he says of those he has dealt with in and out of government."They know we don't talk for the sake of talking."

All these years later, he still won't talk, he says, "about those conversations we had with Bobby."

Castro recognized him as special, too. Oliva was a particular problem for the Cuban leader. Castro always called members of the brigade mercenaries, killers paid by the United States. He said their ranks were composed of reactionaries unrepresentative of Cuban society. There were virtually no blacks among those who invaded, he would say in speech after speech. Yet Oliva, the brigade's most celebrated member, was black, a career soldier who served Castro as a general inspector of agrarian reform throughout Cuba before breaking with him and fleeing into exile.

Oliva recognizes his own more limited outlook in those days. "Maybe we were naive at that time," he says. "We have grown up; I myself, as an individual, have grown up. At that time I thought only in one direction -- the military way. Now I think I see from other sides too -- the political and the economic as well. I'm sure most of the members of the brigade have grown up -- except the problem we have with some of those whose clock stopped in January 1959 [when Castro came to power] who are still thinking about what they left in Cuba. There have been so many changes; we can never go back to just what it was before."

That wasn't the way he and the others felt when they emerged from prison. Suddenly Oliva and a handful of others found themselves dealing directly with the highest levels of the U.S. government. Only minutes after returning to Florida he was talking by phone to Robert Kennedy in Washington. In the next few days he twice met President Kennedy privately while JFK was sailing in Florida. In that dramatic ceremony in Miami's Orange Bowl just after Christmas of 1962, it was Oliva who presented Kennedy with the flag of the brigade, and heard the president emotionally promise to give back the flag to the brigade in a free Havana.

CIA money was still flowing to the Cubans, plans were under way for further covert activities and training camps. "What came to our mind at that time," Oliva remembers, we 'We are in business.'"

He and many Cubans went into the U.S. Army; others withdrew into the shadows of the CIA. Oliva was designated by President Kennedy as representative of the Cuban officers and enlisted men in the Army. He graduated from virtually every school the Army offered -- infantry, artillery and missiles, airborne, maintenance and language. He was assigned to the Office of the Secretary of the Army, and worked under Joseph Califano and Califano's young deputy of the time, Lt. Col. Alexander M. Haig, now the secretary of state. Then, Oliva was suddenly "out of business."

Kennedy was dead, Lyndon Johnson was president, and the administration had other ideas about Cuba. At Robert Kennedy's request, LBJ gave Oliva the word about the end of special U.S. aid for the Cubans at a private White House meeting attended by only the three men. He stayed on in the Army, went in with the paratroopers into Santo Domingo, and then left the service. For the last decade he has worked for the District of Columbia government, first as a human resources coordinator, and now as acting chief of that department's developmental disability division.

By some curious coincidence his office on H Street stands just three blocks away from the old Ebbitt Hotel.

Now middle-aged, graying at the temples, dressed in a three-piece, dark pin-stripe suit, the father of a premed student at Georgetown University and a high school freshman, a suburbanite in nearby Maryland, he looks every bit like a hard-working D.C. bureaucrat. But he's kept his hand in other ways, too, these last years. He now holds a master's degree in Latin American affairs from American University, and is a graduate of both the Army's Command and General Staff College and the Army War College, the only Cuban with that distinction. He's also presently commanding officer of the 260th Military Police Group of the D.C. National Guard. "Maybe the time will come when I can be useful," he says.

After the survivors had been rounded up in the swamps that spring of 20 years ago, John F. Kennedy spoke of "the sober and useful lessons" of that episode. They are different today from the ones he drew then, but nonetheless sober and useful.

Oliva, understandably, puts them more personally. Members of the brigade have been involved in every American military action since the Bay of Pigs. Some, like himself, went into Santo Domingo. Some died in Vietnam. Some flew surreptitious missions in the Congo or served clandestinely in Angola. Some, at the top, have been murdered -- a number of them in mysterious circumstances in Miami. Some have been involved in drug dealings, some in gambling, some are in prison. Some have become terrorists, anti-communist zealots who will take any action to attack Castro and Russia. Some have become millionaires. One became head of the Democratic Party in Florida. "There are a hundred different stories," he says, "but the successes have been more than the failures."

As for himself, he still feels the old frustration.

"Frustration. You see, I have used many times the word frustration. I never have felt betrayed. I told you in 1963, and I have told you all these years since, why I never felt betrayed. It is because I was a Cuban nationalist fighting for a Cuban freedom with Cubans beside me. I am only frustrated that my allies, my friends, didn't do what they were supposed to do. fThey didn't do what they told us they would do."

Would he get on that same ship today if given the chance? A smile, a pause, a reply:

"No, I have learned a lot. I would be sure before going out on that ship again that my allies are really my allies, my friends are really my friends, and that I have what I need to accomplish my mission."

But then, of course, the United States would never sponsor such an ill-planned, ill-fated, predestined-to-doom expedition again. Even today, after so many years, it still seems too unreal to be true. Perhaps, like the road that disappeared in the Guatemalan jungles, it never really happened at all.