Everyone who thinks about such things knows that familiar patterns of international relations are changing in fundamental ways, and it is still not clear how governments will relate to one another in the post-Cold War era.

Will Germany be reunified before the end of the year? Will a unified Germany remain a member of NATO? Will NATO survive? Will its function be altered in important ways? Will the 12 members of the European Community agree to monetary, social and political union as well as economic union? Will they construct a strictly European defense pillar? Will the Conference on Security and Cooperation in Europe (CSCE), an organization made up of the signers of the Helsinki accords, assume new functions with regard to European security? Will there be a role for the United States in a new Europe? Will there be a role for Japan in the new NATO?

Governments that know what they want are accelerating their actions now. Last week leaders of several major nations spoke out in the effort to influence the shape of things to come.

West German Chancellor Helmut Kohl and his foreign minister, Hans-Dietrich Genscher, continued their determined drive to remove obstacles to German reunification. Kohl has already overcome French resistance by offering support to a strong European economic, social and political union, and by providing explicit guarantees of the Polish borders. He has already won American support with his continuing assurances of German membership in NATO.

Kohl and Genscher worked last week on Soviet opposition. Genscher reminded Soviet officials not to worry about Germany's NATO membership -- European security will be restructured in any case. Kohl meanwhile demonstrated to Mikhail Gorbachev that he could be a very good friend -- helping get urgent consideration from George Bush and the EC of a new Western aid package for the U.S.S.R. No one need doubt Germany's priorities. They are for a united Germany.

Soviet priorities in Europe are also relatively clear. Gorbachev gives every evidence of continuing opposition to the survival of NATO. Stuck with the Warsaw Pact's disintegration, Gorbachev talks frequently about new security structures for Europe, about the CSCE, about building a common home for a common European family.

Last week there was a new formulation: The Soviet Union would not oppose German membership in NATO provided Germany's status was like that of France. But as French strategist Francois de Rose reminded us, France is not a full member of NATO. There are no foreign troops stationed in France. Gorbachev's motives are not important, wrote de Rose in Le Figaro, ''For us, it remains the fact that under the cover of a defensive concern for the security of the U.S.S.R., the Soviet president has mounted an offensive which would destabilize the Western defense position in Europe.''

France's president, Francois Mitterrand, expressed more solicitude about Gorbachev's strategic concerns. ''It is of capital importance not to inspire a Soviet fear of encirclement,'' he said in the course of a long discussion of international affairs in Le Monde. In that same discussion Mitterrand made clear that given the present balance of forces NATO is necessary and should be maintained with a unified Germany as a member. But his heart isn't in it.

Mitterrand sounds more and more like Charles de Gaulle when he speaks of foreign affairs. ''I hope that one day Europe will assume responsibility for her security. But that is not practical now. So let us think and work toward that day.''

Mitterrand has persuaded himself that the route to a stronger France is through Europe. ''The France that is part of Europe will be stronger and more influential than France alone,'' he told Le Monde. He looks forward to the not-too-distant day that the EC will achieve economic, monetary and political union. ''We are at home in Europe.''

Margaret Thatcher is less comfortable there.

''We are not prepared to drop the pound sterling,'' she said last week. ''One day, I don't know, in the long distant future there may be a single currency. I don't think it is for our generation to take that decision.''

Thatcher has more residual concern than Mitterrand about resurgent security threats from the Soviet Union and Germany and is far more attached to NATO and the Atlantic Alliance.

These are the policy priorities that dominate the diplomatic scene in Europe today. Germany wants unification at almost any price. The Soviet Union wants NATO dismantled. France wants a strong Europe. Britain wants a strong Atlantic Alliance. And to further complicate the scene, Japan, which officially attended its first high-level NATO meeting last week, wants in to Big Power decision making on Europe as well as the Far East.

Each country also desires to strengthen the institution in which it is, or hopes to be, strongest. France seeks to strengthen the EC; Gorbachev wants an all-European forum (CSCE); Britain values NATO, and Germany will settle for any terms necessary for reunification. Japan thinks that just maybe the annual economic summit meetings of the seven leading industrial democracies (where it just happens to be present) should extend its concerns to the coordination of Western security policy.

And the United States? What do we think, and what do we want? The survival of NATO? A U.S. role in Europe? A cohesive, unified Europe of the 12, or a looser, more expansive union of the Western democracies? Would a trilateral structure suit us better?

What kind of role do we want, and what kind of international structures? Time and the opportunity to influence events are slipping away.