Andrei Parastaev, first secretary to the Soviet ambassador, turned away from the stiff wind on 16th Street outside the embassy gates, faced the Americans, and issued the verdict: "Twelve. Twelve only. Please, not one more."

The official spoke yesterday to a group of Soviet and American World War II veterans, men who had fallen into one another's pounding embraces at war's end, men who had guzzled schnapps and traded wristwatches and medals in wild celebrations of victory over the Nazis at the River Elbe in Germany on a spring day in 1945.

This was not a group that would take well to an arbitrary rule, not when they had traveled from Ohio and California and Moscow and Minsk to be reunited with their friends, their allies, of four decades.

Bill Beswick of West Point, Va., tugged on his baseball cap decorated with Soviet and American pins and told Parastaev, "If my wife doesn't go in, I don't go in."

Moments later, Parastaev led the way as the entire delegation -- 15 Americans and three Soviets -- climbed the embassy's grand staircase, passing beneath a glaring portrait of Lenin and on into a reception with Ambassador Yuri Dubinin. "That is the spirit of the Elbe at work," Beswick said, winking at his wife.

On short notice, the organizers of the Kansas-based Elbe Alliance had set up this reunion, which includes a banquet, meetings with schoolchildren, tours of Washington and scores of sessions with members of Congress and other politicians.

Everywhere they go, the knot of mostly white-haired men -- a retired neurosurgeon, a psychologist, a bookseller and their friends, a school principal from Minsk and a professor of engineering from Moscow -- carry copies of a famous Life magazine photograph.

It shows two beaming soldiers, Bill Robertson and Alexander Silvashko, locked for the first time in a firm embrace and a handshake made clumsy by excitement. Yesterday, Robertson and Silvashko went down for breakfast at the Omni Georgetown hotel, embraced in a thundering hug and immediately assumed the pose, their arms sliding easily into that odd hold that became frozen in history.

In three hours yesterday morning, the two men slipped into their pose dozens of times.

"Thirty years went by without doing that," Robertson said. "And in the past few years, we've done it thousands and thousands of times."

Silvashko roars with joy each time he does it. He is much rounder now, with a ruddy face and an uncertain gait. But Robertson said he recognized his friend instantly when they were first reunited in Moscow in 1975. "It's pretty hard to miss that sharp nose," he said.

On that April morning in 1945, Lt. Robertson crossed a bridge over the Elbe at Torgau with his patrol in what is now East Germany. The Soviets 500 yards beyond began to fire, even after the Americans raised a Stars and Stripes fashioned from a bed sheet.

"They fired at us for an hour," Robertson said. "We later found out that the Germans had played a trick on them two days earlier. Some SS men making a last stand had waved an American flag then shot down the Russians who had eagerly come out to the river . . . . "

Only by bringing forward a liberated Russian prisoner to shout the truth did the Americans get the Soviet forces to believe them.

"And when they did, my God, they produced schnapps, we traded trinkets and our service watches," Robertson said.

One Soviet soldier gave Robertson his wedding ring.

The next day, Silvashko and Robertson went to American division headquarters, where they posed for the Life magazine photo.

The ecstasy of victory was shortlived. Within weeks, fences were erected and strict antifraternization rules imposed. The men of the Elbe had no further contact until 1955.

That first reunion was dangerous, especially for Americans who risked the suspicion of McCarthyism to venture to Moscow at the height of the Cold War. Joseph Polowsky, a Chicago taxi driver who almost singlehandedly kept alive the memory of the Elbe, organized that trip and unsuccessfully pushed for other commemorations.

In 1983, the East German government fulfilled Polowsky's wish to be buried near the Elbe at Torgau. Veterans from the U.S. and the Soviet Union served as pallbearers.

Since then, the veterans have met several times, at Torgau in 1985 while President Reagan made his controversial visit to a German cemetery at Bitburg, and last year in Geneva during arms talks.

But the summit, with all its hope for peace, is the most emotional reunion yet, several veterans said.

"Nobody could have thought in our lives that we could have two great meetings," said Major Gen. Alexander Olshansky, who was with the first group of Soviets to link with an American patrol. Olshansky and the others stood among charred bodies of German war victims and swore to do all they could to prevent another such war. "We have a trust which cannot be destroyed by time," said the military man turned professor.

The Elbe Alliance and Soviet veterans groups have stepped up their efforts recently. Next year, "Yanks Meet Reds," a book of first-person accounts and photos of the Elbe meetings, is to be published here and in the Soviet Union.

"When I see surveys showing that half of young Americans think we fought against the Soviets, I know we have to get our message of the Elbe across to a new generation," Robertson said.

But while the Soviet government routinely celebrates the Elbe as a symbol of friendship between the two countries, the veterans say the United States has been reluctant to help. The Soviet ambassador immediately agreed to meet with the group, and the Soviet press regularly reports on the veterans' activities.

"We've never received anything from the American administration in the way of support," said Mark Scott, cofounder of the Elbe Alliance. "I don't think they know what to do with us, with all this history and the passions that are still alive."

The session with the Soviet ambassador was heavy on emotion. Standing before a copy of the Life magazine photo, Dubinin watched Robertson and Silvashko reenact the pose and said, "Just as in '45. I was a boy, but I remember the meeting very well. How was it, this very first meeting?"

With that, the old soldiers turned from the coffee and cookies and broke through the careful language of diplomacy, telling their stories as if for the first time. They roared over the memories of schnapps that appeared from nowhere. They relived the exchanges of pins, the back-slapping, the sudden ability to communicate without words.

When Dubinin ushered them out, and they walked past a guard booth manned by a Soviet soldier, and past an office where aides watched Secretary of State George Shultz on TV discussing nuclear weapons, the veterans embraced again.

"This is all about hope," Robertson said. "Hope is important for a man."