COMBAT IN PANAMA : At the United Nations, the Revolution Is Continued by Fax : Diplomacy: Eduardo Vallarino learns he is the new ambassador. The Harvard scholar has twice fled his country.

He walked into the United Nations building, like thousands of ordinary tourists, with credentials so fresh they had to be transmitted electronically from the new U.S.-backed government of Panama.

Only hours earlier, Eduardo Vallarino had been telephoned in Cambridge, Mass., by Panama’s two newly appointed vice presidents, Ricardo Arias Calderon and Guillermo (Billy) Ford--the latter being the man with whom Vallarino had spent a tense afternoon in a Manhattan hotel room in October, sweating out the unsuccessful coup against the regime of Gen. Manuel A. Noriega.

The news in the phone call was stunning and the message simple: Noriega was under attack, and Panama’s new president, Guillermo Endara, wanted Vallarino, an associate member of Harvard University’s Center for International Affairs, to be Panama’s new U.N. ambassador.

With informality built upon necessity, Vallarino rushed to Manhattan, picked up his credentials Wednesday and delivered them to the 38th-floor offices of U.N. Secretary General Javier Perez de Cuellar.

“The credentials came by fax,” the 51-year-old fledgling diplomat said with a smile. “It’s a fax revolution.”

But as far as the United Nations is concerned, it’s an unfinished revolution.

Just four blocks away, Noriega’s hand-picked ambassador, Mirla Bellavita, stubbornly remained in Panama’s plush U.N. mission. For the time being, Vallarino was prepared to wait her out.

“We are all Panamanians,” he said. “The Noriega show is over. We have to pull together. We have to resurrect the country and avoid hard feelings.”

On Thursday, Vallarino walked across First Avenue from his hotel room to hold his first news conference at the United Nations. He was escorted by a member of the U.S. mission’s staff.

Vallarino said he was seeking permission to address the Security Council and that he had talked by phone once again with Panama’s two vice presidents, who reported that they had accompanied Endara to Panama’s Legislative Assembly building and were planning to visit the presidential palace later Thursday.

Vallarino defended the legitimacy of his appointment as the representative of leaders elected “by at least 75%” of the voters in last May’s annulled elections. He also said that he regretted the need for U.S. military intervention to install the new government.

“It has been very costly, not just in lives,” he said of the military action. “It sets both countries back in history where we never wanted to be.”

He blamed Noriega for “opposing every opportunity to transfer power peacefully.”

“I would point the finger at Noriega himself and then at those democracies who didn’t help Panama,” Vallarino said.

Shortly after arriving from Massachusetts on Wednesday, the newly named ambassador sat in his hotel room listening to a telecast announcement of the $1-million bounty the Bush Administration had offered for Noriega’s capture.

“That is surprising,” Vallarino told a reporter. “Frankly, I think they will turn him in just the same for 10 cents. He (Noriega) is supposed to have hundreds of millions. Some people claim he has $1 billion.

” . . . I see a death wish in Noriega,” he continued. “All through those years, we kept on saying: ‘All we have to do is wait for him to destroy himself. . . .’ ”

The general “would do things totally nuts,” Vallarino said. “He didn’t have to declare war on the United States . . . and he didn’t have to harass the U.S. troops. It is a complicated mind, that of Noriega.”

For these reasons, Vallarino said, many members of Panama’s opposition believed that they “had a perfect target in Noriega.”

A Panamanian psychiatrist who lives in the Boston area drew up a psychological profile of the dictator, Vallarino said. “He had been predicting for months: ‘Don’t worry, he will take care of himself and self-destruct.’ ” Had Noriega “been a little more careful and not harassed the United States the way he did--1,000 incidents of harassment in 1988, for what reason? In a way, he was asking for this.”

Vallarino, who holds an engineering degree from Louisiana State University and a master’s degree from the Harvard Business School and who twice was forced to flee Panama, said that even though some of Noriega’s followers may still control some government offices, physical presence offers no legitimacy.

“There is no following,” he said. “They have a shell. But that’s bound to crumble at any minute. . . . A building does not mean anything. They can stay in there until it is time to move out, which will be shortly. The essence of government is not the buildings. It is who follows you.

” . . . I think that we as a country, all of us have learned a tremendous lesson, not because of the military intervention right now. Living out of democracy for a couple of decades teaches you that you had better do things really well and not tamper with the system, which has been a Panamanian sport in the past. I think there is quite a bit of awareness of that.”

When he first received word of the attack on Noriega, Vallarino had not been to bed for almost two days. He had just returned to the United States from Chile, where he was an observer of that country’s elections.

Despite a shortage of sleep, he seemed at ease. “Anxiety is out. It isn’t like October,” he said, referring to the unsuccessful coup against Noriega. “We had all kinds of reservations. We did not know who those people were,” a reference to the military officers who rebelled against the general.