PEACEKEEPING : U.N. Looks to Celebrations of Its First 50 Years : Officials ponder the world body’s future at a gathering to commemorate the conference that led to its birth.

Almost like history repeating itself, American officials handed out documents to delegates recently in elegant, secluded Dumbarton Oaks, setting down the U.S. government’s ideas for dealing with disorder in a strange new world.

Half a century ago, in the wartime summer of 1944, Secretary of State Cordell Hull called delegates from Britain, the Soviet Union and China to Dumbarton Oaks to discuss U.S. proposals for a new international organization to police the world. That conference led to the creation of the United Nations a year later.

To commemorate the 50th anniversary, the trustees of Harvard University, who own Dumbarton Oaks, convened scholars, diplomats and officials last weekend in the famous 19th-Century mansion to discuss the creation, achievements, failures and future of the United Nations.

The conference was also a prelude to myriad events that will celebrate the 50th anniversary of the United Nations next year, culminating on Oct. 24, 1995, when chiefs of state and government will flock to New York to mark the day that the world organization officially came to life.

The anniversary year will also feature a gathering of Nobel Peace Prize laureates in San Francisco, where delegates from 50 nations signed the U.N. Charter on June 26, 1945; a world tour by London’s Royal Philharmonic Orchestra, special stamp issues, and a host of publications and conferences.

None of the future celebrations, however, is likely to have the special, shadowed charm of Dumbarton Oaks. The mansion, with its collection of art and 10 acres of sculpted gardens on a hill in Washington’s wealthy Georgetown neighborhood, was donated to Harvard by retired U.S. Ambassador Robert Woods Bliss in 1940. The State Department borrowed the site for the momentous conference four years later.

The anniversary meetings came just a few days after President Clinton signed Presidential Decision Directive 25--a skeptical U.S. assessment of U.N. peacekeeping missions in the post-Cold War era and the limited role that the United States envisions for itself in such operations. U.S. officials took advantage of the timing to pass out detailed explanations of the directive to the conferees.

The skepticism struck an ironic note, because no one was as enthusiastic about multilateral policing of aggression and turmoil as the U.S. delegates to Dumbarton Oaks 50 years ago.

Britain’s Michael Howard, president of the International Institute for Strategic Studies and a retired Yale University historian, said the 1941 Atlantic Charter signed by President Franklin D. Roosevelt and British Prime Minister Winston Churchill first raised the idea of a future system of collective security.

“Now this vision of the postwar world was quintessentially American,” Howard told the delegates last weekend. “The British disliked some of it and were skeptical about most of it, but for them the important thing was to get the Americans on board, first as allies in fighting the war and then as associates in keeping the peace.”

The original Dumbarton Oaks conference, while fashioning most of the future United Nations, ended in disagreement on two points--a veto for the permanent members of the Security Council and the number of seats that the republics of the Soviet Union could have in the General Assembly. At Yalta later, Josef Stalin, Churchill and Roosevelt finally agreed to allow a veto and grant seats to three Soviet republics.

But many speakers looked forward last week rather than back. Assistant Secretary of State Douglas J. Bennet had an admonition for those who believe that the United Nations is about to fulfill many of the hopes set down for it at the first Dumbarton Oaks conference.

“Fiftieth anniversaries invite celebration,” Bennet said. “But let us not celebrate an illusion that the Dumbarton Oaks institutions . . . will spontaneously regenerate and start serving mankind as the founders intended.

“Without a fresh interpretation of the forces driving today’s world and without a fresh infusion of vision and commitment, the Dumbarton Oaks institutions may be overwhelmed by forces already loose in the world.”