NEWS ANALYSIS : Gorbachev Bets Future on Friendly Ties to West : Europe: He rejects military might as the basis for Soviet security. Instead, he is banking on enduring peace and economic cooperation.

President Mikhail S. Gorbachev has been telling the Soviet people for nearly five years that friendly international relations are a better guarantee of the country’s security than military might.

Now, he is betting the country’s future--and his own--on such a bargain.

In agreeing this week to NATO membership for a reunified Germany, Gorbachev put his “new political thinking,” today’s basis of Soviet foreign policy, to its toughest test.

Moscow, in essence, is trading the security provided by 360,000 of its best troops, those stationed in East Germany, against the promises that West German Chancellor Helmut Kohl made about enduring Soviet-German friendship, future economic cooperation and a peaceful Europe.

This is not a deal that any Soviet general would have seriously contemplated a year or so ago, simply because of the massive changes it will bring to the Soviet Union’s front-line forces. Yet it will probably prove acceptable here.

Some audible grumbling is likely among the Soviet military, but the Communist Party controls its promotions. Those conservatives worried about the collapse of socialism in Eastern Europe might discuss, once again, the replacement of Gorbachev before deciding that only he can lead the country.

The Soviet calculus, so typical of the new perspective that Gorbachev has brought to international relations, turns his reluctant acceptance of Germany’s membership in the North Atlantic Treaty Organization into not so shabby a deal for Moscow.

While Gorbachev unquestionably yielded on the immediate issue, German membership in NATO, he had won over the course of the past year and a half a fundamental reorientation of the Western alliance, a Soviet goal for many years.

He agreed to the withdrawal of Soviet troops from East Germany but won a 35% cutback from the current level of West German forces as well as further pledges on curtailing NATO deployments and German armaments, all of them reductions that NATO has resisted in direct negotiations with the Warsaw Pact.

And he shifted relations between Germany and the Soviet Union from that of adversaries, past and potential, to allies. Moscow hopes to be perceived as encouraging, not opposing, German unification and its subsequent role in the shaping the new Europe.

Drafting is already under way on a Soviet-German treaty of peace and friendship, and West Germany has pledged $3 billion in bank credits and as much as $1.5 billion a year in grants to support the remaining Soviet troops in East Germany.

“The worst thing we could have done would have been to try to bar the door to reunification,” a senior Soviet foreign policy specialist commented Tuesday. “First, it would have been futile, and we all knew that. Worse, we would have cast ourselves forever in the role of enemies.

“In fact, we see benefit from a strong and united Germany--as long as it is peaceful, and please underscore peaceful-- while Britain and France are already agonizing over this ‘new German order’ and how they will be eclipsed and turned into second-rate powers. Mikhail Gorbachev will be remembered in Germany as the man who helped make reunification happen.”

Far from the unilateral surrender that many Western commentators saw, Moscow’s historic deal with Bonn was based on a realpolitik , as Gorbachev noted, through which the Soviet Union remains a major player even when it seems weak.

The essence of Soviet logic lies in a series of far-reaching assessments, projections and judgments that have altered Kremlin foreign policy across the board in the past five years:

From its earliest days, the new Soviet leadership under Gorbachev recognized that the country could not sustain its role as a global superpower. Not only was it overextended militarily, but the financial cost of keeping up with the United States was undermining the whole economy. The Soviet Union had first to pull back and then to make friends with countries it had earlier called enemies.

The European continent is the natural home of Russia, as the Soviet Union was known before the 1917 Bolshevik Revolution and perhaps will be known again soon, and the country must not be shut out of the rapid political, economic and social consolidation under way here. Most of all, it must ally itself with Germany, certain to be the Continent’s other dominant power after its reunification.

The Cold War security system of opposing alliances, buffer states, the Iron Curtain and the Berlin Wall had to be dismantled. It could only be sustained at a now unacceptable cost--the military reimposition of Soviet-style socialism on Poland, Czechoslovakia, Hungary and East Germany. The Soviet Union itself had lost faith in that system, and its people had no stomach for imposing it on anyone.

Germany’s reunification, accepted in principle by the Soviet Union last fall as the natural right of a sovereign people as well as a political inevitability, immediately implied that Germans have the right to determine their unified state’s foreign policy. And, if that meant NATO, as all knew it would, then a way would have to be found to make that deal.

In the end, winding up two days of talks with Kohl, Gorbachev found himself backing into formal Soviet acceptance of NATO membership for a unified Germany.

“A united Germany will achieve full sovereignty,” Gorbachev told a news conference, which was broadcast live here. “It is entitled to make use of that sovereignty, to make its own choice, both on internal matters such as its option for social development and in terms of what it may want to participate in, in which alliances, what links it wishes to maintain, with whom it may wish to establish or renew relations. All these are signs of the full sovereignty that the state will acquire.

“Do you remember,” he continued, “that at one time I put forward the idea that, whether we like it or not, a time would come when a united Germany would actually be part of NATO if that is its choice? But, even if its choice is that, to some extent and through certain two-way links set down . . . it will be cooperating with the Soviet Union and thereby with a significant part of the Warsaw Pact.”

Awkward as it may have seemed to a Western audience, this explanation put into perspective for the Soviet viewer the reversal of the “no-never” approach to German reunification that Moscow had taken for more than 30 years. Under this logic, Germany’s NATO membership would be the result of Soviet observance of such sacred principles as national self-determination and non-interference in another country’s policies.

These and similar assessments were made months ago, in fact, in the foreign policy think-tanks of Moscow, and Gorbachev’s acceptance of German membership in NATO was actually ordained here late last year when he accepted German reunification. What was in doubt, according to Soviet foreign policy specialists as well as Western diplomats, was what the Soviet Union would get in return.

Although camouflaged by circumlocutions, Gorbachev’s words were quickly translated by every Soviet viewer into three basic issues--the security of the motherland, the trustworthiness of the Germans and the balance of power between East and West.

Soviet attitudes toward Germany are complex but not difficult to understand.

After two wars in this century as the result of Germany’s political, economic and territorial ambitions, Russians want to make sure there is not a third. The last cost 27 million Soviet lives, according to recently revised estimates.

The arms reduction agreements that Gorbachev won are intended to ease those natural concerns as well as reassure the Soviet military that the country’s security remains undiminished as its front line shifts eastward to its own borders.

All this may be made more palatable because Russians admire Germany as a productive and hard-working nation. Despite the intense feelings over World War II, Soviet opinion polls show no serious opposition to German reunification and to Germany assuming its “rightful place” in Europe, although always on the premise that the process is peaceful.