HAVANA — Forty years after one of the most notorious battles of the Cold War, former foes from the failed 1961 Bay of Pigs invasion of Cuba came face-to-face Thursday for the first time to share experiences and research.

The U.S. delegation to the three-day conference titled "Giron: 40 Years After" included Cuban exiles who participated in the 2506 Brigade's doomed landing, ex-CIA agents who backed them, and then President John F. Kennedy's sister, nephew and some aides.

They began two days of ostensibly academic — but also emotionally and politically charged — sessions with their local counterparts, led by one of Cuba's senior commanders at the Bay of Pigs, Jos Ramon Fernandez, who is now a vice president in President Fidel Castro's government.

"This is not only a historical conference but a historic conference," said Peter Kornbluh, of the U.S. National Security Archive, who helped organize the American delegation.

"It brings us together in a dialogue that stands in great contrast to the bitter antagonism of the episode itself."

In a remarkable act of reconciliation, the delegations will revisit together Saturday the beaches, known in Cuba as Playa Giron and Playa Larga, where Castro's troops defeated the 1,500 invaders within 72 hours of the April 17, 1961, landing.

They may well be joined by Castro himself, who directed his troops from a tank and visited the front during the battle, which was one of the most notable flashpoints in 42 years of U.S.-Cuba hostilities since his 1959 revolution.

Former Kennedy adviser and historian Arthur Schlesinger said he hoped the conference would "enrich and complete the historical record of this sad episode." He also noted the affinity sometimes felt by participants in a major historical event, even when they were antagonists.

Castro's victory at the Bay of Pigs was a severe blow to Kennedy, whom many Cuban Americans have never forgiven for not supporting the 2506 Brigade more directly as they landed, despite initial CIA training and financing for the invasion.

About 120 Cuban Americans were killed and nearly all the others taken prisoner. The government death toll was 156.

For Cuba, it is remembered as one of the greatest moments of Castro's rule, and a seminal event in protecting the "revolution" against "imperialism." In Florida, the event is perhaps the bitterest memory of all for anti-communist exiles.

Alfredo Duran, one of five ex-combatants of the losing 2506 Brigade attending the event, said their participation had brought "some very difficult criticism" from the Cuban American community in Florida, known for its hatred of Castro.

He made clear, however, their intention to counter the oft-repeated official Cuban line that the invaders, almost entirely Cuban Americans who had left after the 1959 revolution, were "mercenaries" promoting U.S. aspirations to annex Cuba.

"They were honorable Cubans on both sides, people who loved their fatherland on both sides," he said at a news conference on the eve of the event. "We did not disembark thinking we were serving any foreign interest ... We thought it was our duty."

With both sides set to release new declassified documents on the battle, Schlesinger gave an early insight into how the invasion unfolded from Kennedy's point of view.

Kennedy would never have initiated such an "adventure," but having inherited the idea from his predecessor, President Dwight Eisenhower, he was reluctantly "trapped" into backing the invasion plan, Schlesinger said.

The debacle taught Kennedy "a great lesson," Schlesinger added, "not to pay much attention to any recommendations from the Joint Chiefs of Staff. That is one reason why the (1962) Missile Crisis was handled so superbly."

Kennedy apparently rejected military advice during the Cuban Missile Crisis to invade the Caribbean island, preferring to negotiate with Moscow over the removal of warheads.

By 1963, Kennedy was actually exploring a rapprochement with Cuba, "but this was terminated by the bullet in Dallas," Schlesinger added.

Cuban vice-president Fernandez paid tribute to the Americans for deciding to come to Havana for the conference.

And he said Cuba had nothing to fear from the release of declassified documents, even some critical of local troops, because "we have the truth in our hands."

Questions the Americans are keen to ask during the mainly closed-door sessions include: How much did Cuba know in advance of the invasion? Did Castro's security services penetrate the brigade? Was there any Russian involvement?

For their part, the Cubans want to know if the invaders might have won with U.S. air-support, how much Washington really participated behind the scenes, and what other operations were going on to divert attention from the beaches.

Though the conference was initiated and organized by Cuba, there are no indications the communist-ruled nation is restricting the discussion. American participants appear to be freely expressing their insights and views.

Havana hopes to use the conference and next month's actual anniversary, however, to remind the world how it continues to suffer U.S.-led aggression, including economic sanctions.

"The interventionist nature of that battle has continued to characterize U.S. foreign policy up to now," Fernandez said.