He had planned it down to the last detail, and in the end, as one observer put it, "it was like picking cherries, one by one."

In a region of the world known for strife rather than compromise and factionalism more than unity, Costa Rican President Oscar Arias Sanchez seemed to be setting himself up for failure when he tried to sell his vision for regional peace to the other four Central American heads of state. But Arias' idea became reality in August, 1987, when the presidents of Honduras, Guatemala, El Salvador and Nicaragua met with Arias in Guatemala City and signed the treaty.

The plan that Arias calls a "risk for peace" has captured the world's imagination. Largely for that effort, Arias was awarded the Nobel Peace Prize on October 13, 1987, becoming the first Central American ever to receive the award. In the process, Arias, who will deliver today's Commencement address, has become something of a hero to the people of his country and his region.

According to a variety of experts on Central America, the means by which Arias pulled off the dramatic agreement reveal his talents as a skillful negotiator. They add that Arias' pragmatic idealism is in many ways reminiscent of John F. Kennedy '40, a man whom Arias has chosen as a role model.

To pull off his gamble for peace, Arias employed a variety of tactics, each designed to pull in different nations. He also had no compunction about scrapping traditional procedures when they threatened the August meeting's success.

The site of the meeting ensured that at the least Guatemala, as the host country, would back the negotiating strategy.

By including language in the plan casting doubt upon the legitimacy of all insurgent movements in the region, Arias won El Salvador's support.

But the key to the plan was Nicaraguan leader Daniel Ortega. An earlier meeting in February had included all the nations except Nicaragua, but everyone knew--none better than Arias--that unless Ortega signed on, the accord would have no substance.

At Guatemala City, the foreign ministers of the five nations held preliminary meetings but were unable to reach a consensus. Although ordinary procedures called for the ministers and the presidents to meet all together, Arias arranged for the five leaders to meet alone.

Arias confronted Ortega head on, asking him if he was willing to make concessions, says Peter Hakim, staff director of the Washington, D.C.-based think tank, Inter-American Dialogue. If not, then it would be better for the leaders to go right to dinner and cut the meeting short, Arias said, according to Hakim.

Such a direct statement at the start of the talks set Ortega off balance, Hakim says, and led him to make the concessions necessary to sign on. Now only Honduras remained. Though hostile to the plan, the country risked being the "odd man out," Hakim says, and Arias emphasized that danger. As a result, Honduras, too, signed on to the Arias plan.

Arias' behavior was a case study in grace under pressure, experts say. And that description, which was often applied to Kennedy, would surely please Arias, who in many ways has modeled himself after the late president.

Arias was a summer school student at Harvard while Kennedy was president, and by his own account, he took Kennedy as his guide after meeting the presidential candidate on Cape Cod in 1960.

University Marshall Richard M. Hunt says the Costa Rican has expressed a special pleasure at being invited to give the Commencewment address because he sees Harvard as "President Kennedy's university."

In many ways, Arias' background is similar to Kennedy's. The son of one of Costa Rica's wealthiest coffee-trading families. Arias studied in both Europe and America and is known for his strong interest in cultural pursuits and intellectual life.