The last ten years have been the most transparent in the history of the United Nations. Scholars, reporters and the public learned more about the machinations behind UN scenes than they ever had before. But that openness may be difficult for Ban Ki-Moon, the new Secretary-General, to maintain.

Ban is a veteran South Korean diplomat, and diplomats are notorious for their joy at working in secret and commenting afterwards in words of mush. In one of his first interviews, Ban boasted to Warren Hoge of the New York Times that the press in South Korea used to call him "the slippery eel" because "they could never grab me."

Much of the recent openness may thus prove transitory, a reflection of the personality of Kofi Annan, a man of extraordinary candor who believed in the power of understanding. Yet it would be a disaster if the UN returned completely to the foolish darkness that once enveloped it.

When I first covered the UN in 1991, Javier Pérez de Cuéllar of Peru was Secretary-General. He was adept at mumbling to reporters in fluent English, Spanish and French without saying anything. A wag once described him as a man who "wouldn’t make waves if he fell out of a boat." At the daily news briefings, his spokesmen read out official UN statements and refused to elaborate. They parried questions from reporters like hunters hitting quail. When the Secretary-General issued a report to the Security Council, it was kept from the press until the ambassadors digested it, perhaps three days later, when it was no longer news.

During the last few months of his ten-year administration, I proposed that Pérez de Cuéllar discuss his accomplishments in a question and answer session with the Los Angeles Times. In those days, the Times would run the text of Q and A sessions on a full page of the editorial section every Sunday. American politicians loved these pages because their replies ran in full without any outside editing or comment. But, when I made my proposal to Pérez de Cuéllar’s spokesman, he said, "Impossible!" I implored him to ask the Secretary-General. He looked at me with some disdain and scribbled the newspaper’s name on a pad. I never heard from him again.

Boutros Boutros-Ghali, the Egyptian who succeeded Pérez de Cuéllar as Secretary-General in 1992, was a brilliant scholar with an encyclopedic grasp of many issues and subjects, but modern public relations was not one of them. He reigned like a 19th century prince. He talked with a few journalists he favored but not with the rest.

Like his predecessors, he kept his spokesmen in the dark about most things. When Sylvana Foa was asked to take over as chief spokeswoman, she demanded he first pledge to keep her fully informed. He promised to do so but never kept the promise. He barely kept his lieutenants informed. "There is a joke," said an ambassador on the Security Council, "that whenever the Secretary-General wants to look for someone he can trust, he stands up on his two feet, walks across the room to the wall, and looks into the mirror."

Boutros-Ghali cared so little for public relations that he refused to defend himself and the UN when Washington made him the scapegoat for the Somali debacle of October 1993. The 18 American soldiers who died in a raid in Somalia had been under the command of the US military, but the Clinton Administration’s spin made it seem as if they were under UN command. When Deputy Spokesman Ahmad Fawzi, a fellow Egyptian, begged him to correct the record and defend the UN, Boutros-Ghali refused. "..We are here to serve the member states," he told Fawzi. "You cannot go out and blame a member state for an operation that goes wrong. I forbid you from doing that."

"I started calling him the Sphinx," Josh Friedman, who had been the UN correspondent for Newsday, told a conference of former spokesmen and correspondents in 2005. "I never really met him. I covered the UN all that time and I never once met the man or shook his hand. It made it very difficult to do my job."

As soon as Annan was elected to take Boutros-Ghali’s place, Friedman sat down with the new secretary-general to chat for a half-hour. "From that moment," said Friedman, "the guy had me. Anyone who could care enough to be human to someone else — there had to be some good qualities. And I think a lot of the press felt like that."

Of course, Annan had his troubles with the press sometimes. When his son Kojo’s name was besmirched in the oil-for-food scandal, the Secretary-General clamped his mouth shut. Transparency, in his view, should go only so far. Family matters were private, off limits, shrouded in darkness.

Despite this, reporters and, in fact, scholars have never had such open season as they had during Annan’s two terms. He held many news conferences, kept his door open for interviews, chatted with reporters in the corridors, and appeared on many television talk shows. He allowed his spokesmen to attend the daily cabinet meetings and encouraged them to brief reporters on what was going on.

On top of this, he appointed commissions to investigate a trio of UN failures: the massacre of Tutsis in Rwanda, the slaughter of Muslim men and boys in Srebrenica, and the lack of oversight of the oil for food program. The commissions issued voluminous public reports that laid bare secret UN cables, phone calls, e-mail messages and conversations that revealed how UN officials work in crises. The UN has never been so exposed before.

Some positive signs have come recently from Ban Ki-Moon. He appointed a celebrated Haitian journalist, Michèle Montas, as his spokeswoman. She and her husband, Jean Dominique, operated a radio station in Haiti renowned for many years as a beacon of democracy and social justice. But Dominique was assassinated in 2000, and Montas, threatened with death as well, left Haiti three years later and joined the UN information staff. She is a graduate of the Columbia University Graduate School of Journalism, but we do not know yet whether she will be allowed to take part in Ban’s senior staff meetings.

Although he has filled his early news conferences with soporific platitudes, he also has tried to backtrack from his unfortunate image of the "slippery eel." He told reporters recently that South Korean journalists gave him that nickname "because I was friendly with the media. You should understand that. But I promise today that I can be a pretty straight shooter when I need to." He has also promised to encourage his senior staff "to have continuous dialogue with the press."

It is, of course, too early to judge. Ban has held office only a few weeks. But any return to the pre-Annan era when UN officials and diplomats reveled in keeping the press in the dark would only hurt the sorely misunderstood UN. The United Nations needs light most of all.

Stanley Meisler is the author of Kofi Annan: A Man of Peace in a World of War and United Nations: The First Fifty Years.