Diplomats from Eastern Europe used to have a hard time getting inside the heavily guarded NATO complex. Now they are given up-to-the-minute briefings on the Persian Gulf crisis. ``A year ago, just walking around NATO headquarters . . . would have been either illegal or certainly incredible,'' said Tibor Kiss, the Hungarian charge d'affaires in Brussels. He is among diplomats from Eastern European countries that accepted an invitation from North Atlantic Treaty Organization leaders to a ``regular diplomatic liaison'' with the Western alliance. At their July summit in London, President Bush and the other NATO leaders said the West wanted to share ``our thinking and deliberations in this historic period of change.'' They made the offer to the Soviet Union, Czechoslovakia, Hungary, Poland, Bulgaria and Romania, all members of the Warsaw Pact, the crumbling Eastern military alliance. The seventh Warsaw Pact member was East Germany, now part of united Germany, which belongs to NATO. The Soviet Union and Hungary were the first to accept, telling NATO their ambassadors to Belgium would represent them, and the others followed. Diplomats from the six countries have had about half a dozen briefings at NATO, mostly on the gulf crisis. A senior NATO official, who spoke on condition of anonymity, said the briefings illustrated ``the new post-Cold War era that we're in. . . . We are no longer adversaries.'' Henning Wegener, assistant secretary-general of NATO for political affairs, gave the diplomats information on two meetings in August and September of foreign ministers of the Western alliance's 16 member nations. Separate sessions have been held with American officials, including the U.S. Ambassador to Iraq, April Glaspie, and Condolezza Rice, a Soviet specialist at the National Security Council in Washington. No NATO secrets were divulged, said those attending the discussions. ``I would not say these briefings are more informative than the press conferences,'' one diplomat said, on condition of anonymity. Others described them as helpful, especially the ones given soon after Iraq invaded Kuwait on Aug. 2. Kiss said Hungary ``certainly took into account whatever was said by the West'' in determi ning its position on the invasion. NATO is wrestling with the question of how far it should go in contacts with the ambassadors, known in NATO-speak as interlocutors. William H. Taft IV, U.S. representative to the alliance, would like to see the links expanded. ``I would hope . . . that we would at the least go well beyond the idea of simply keeping these new friends advised of major developments when they occur,'' he said in a recent speech. ``The point of liaison is surely something more - indeed, to keep in touch before major steps are taken and to benefit from consultation . . . before decisions are taken.'' Some European countries, notably France, are more cautious. One NATO diplomat, who would not let his name be used, said the invitation was a symbolic gesture ``intended to end the kind of distrust the six countries had concerning NATO. It was important to tell them our door was open.'' Making the contacts more formal, by opening a new NATO office for the purpose or granting the diplomats observer status at meetings, would change ``the real objective of this measure,'' he said. ``We have to have first a real debate in the organization about what we want to do,'' the NATO diplomat said in an interview. Andrei Keline, first secretary at the Soviet Embassy, doubts he ever will observe high-level NATO meetings. ``This is an alliance,'' he said. ``We are not part of it.'' Still, Keline said Moscow feels the links offer potential for military, scientific and economic cooperation. ``NATO is an important organization,'' he said. ``What we want (is contacts that are) business-like. They should be deep, and they should give as much as possible for both sides.'' Hungary, which plans to leave the Warsaw Pact's military arm next year, wants to deal with NATO on its own, not in a group with the other pact members. Could the initial contacts eventually lead to one or more of the Warsaw Pact countries applying for membership in the Western alliance? ``NATO isn't seized with that question because nobody has asked,'' the senior NATO official said. Keline commented: ``I wouldn't bury the (Warsaw Pact) right now.''