NEWS ANALYSIS : Openness, Cooperation Make It a Summit of Superpower Buddies : Diplomacy: Clinton, Yeltsin seemed to engage in a brainstorming session on many of the world’s problems.

When the leaders of the world’s two nuclear superpowers got together and agreed on as much as Russian President Boris N. Yeltsin and President Clinton did Wednesday, the outlines of the New Order seemed to emerge from the post-Cold War fog.

It is a world order in which, in sharpest contrast with the old days, Russia and the United States consult closely on everything from obscure conflicts to nuclear stockpiles. Their leaders come to summits ready to discuss anything and everything.

It is a world moving away from military blocs such as the North Atlantic Treaty Organization and toward open discussion clubs such as the United Nations.

And it could be a world where nuclear arsenals have been so drastically cut that the superpowers can switch to defensive nuclear arms and can finally lay to rest the nerve-racking doctrine of mutually assured destruction. In short, the world could be a safer place.

On Wednesday, Yeltsin and Clinton emphasized that they respect the rights of other nations.

But the summit buddies--both tall, beefy and folksy--almost sounded like co-presidents of the world.

Yeltsin reeled off a list of items the two leaders had harmoniously discussed that included such bones of cooperation as the environment, military doctrines and space exploration.

But the style of the summit went beyond consultations; it seemed to be a Russo-American brainstorming session on the world’s problems.

“The idea is worked out jointly,” Yeltsin spokesman Anatoly Krasikov said of the presidents’ approach to resolving the conflict in Nagorno-Karabakh. “It’s not that Russia says, ‘I think this.’ They work together.”

The two leaders appear to have worked together, in part, on developing the vague ideas Yeltsin broached in his United Nations speech on Monday about moving toward some kind of new global security design, some organization that could replace NATO.

Russia’s interest in liquidating the alliance contradicts the American line that NATO should rather expand to include would-be members in Eastern Europe. But whether the alliance eventually grows to include Russia or evolves into something new, either way, the military bloc system is over.

“I’m personally convinced that the time of NATO is passing, because NATO is the concrete product of an absolutely concrete, specific epoch, the epoch of confrontation,” Krasikov said. “Now some new structures should be created--which ones, I don’t know. I think no one knows.”

The era of mutually assured destruction may be passing too. The Cold War doctrine held that this is the best way to prevent nuclear war: Each side should maintain such weak defenses against nuclear attack that it can never launch a first strike, because it would be devastated by even a weak retaliation.

Now, in both the Clinton and the Yeltsin administrations, talk is mounting of new thinking that could allow the superpowers to put up nuclear shields, at least enough to defend themselves from terrorists’ bombs.

Yeltsin openly relished the announcement that he and Clinton had begun talk of a “START-III,” a follow-on to the two arms agreements that cut the superpowers’ arsenals by about two-thirds.

Their summit agreement to speed up the dismantling of the missiles cut under START II--after it is passed by lawmakers in both countries--showed what impatience they feel about the prospect of moving the world toward nuclear tranquillity.

“This way, we economize seven or eight years and give humanity the hope that our people will probably live in peace,” Yeltsin said.

Judging by the atmosphere at the summit, Cold War graduates are already living in peace.

American officials described an amazingly informal mood in which Yeltsin stripped to his shirt sleeves for some of his long chats with Clinton, leaning his elbows on the table and addressing questions directly to U.S. Cabinet members, as well as to the President.

In the old days, Krasikov recalled, everything would be worked out “to the last comma,” and the leaders would sometimes sign documents without even knowing what they were signing.

Russian and American views differ on lifting the arms embargo in Bosnia-Herzegovina, on whether Russia should have a “sphere of influence” in the former Soviet Union, on arms sales to Iran and other issues.

But by the end of the summit Wednesday, Yeltsin could say: “We agreed on practically all questions. There were some compromises from the United States, some compromises from the Russian side, but for peace, humanity and our Earth, we agreed.”