NEWS ANALYSIS : Soviets Viewed as Crucial to Success of Reunification : Politics: Moscow-German ties seen as the best hope for triumphing over the age-old tangle of animosities.

The agreement signed here Wednesday formally blessing German reunification was rightly celebrated as a watershed in modern European history.

The treaty marks the end of the Cold War era and Europe’s division. It is filled with hope for a future in which reason can triumph over Europe’s age-old tangle of animosities that have twice in this century plunged the world into war.

Whether these hopes can blossom into a peaceful, prosperous, united Europe will to a significant extent hang on the success of one vital relationship--that between a strong, newly confident united Germany and a Soviet Union staggering under the weight of crippling economic problems and potentially explosive domestic political difficulties.

Positive bilateral ties between Europe’s two largest countries would be one of the firmest anchors possible for a stable future, diplomats and political analysts believe.

But such ties will not come easily. Anyone watching the carefully ordered rhythm of the German press corps collide with the realities of Moscow’s chaos in the last two days could understand the totality of the cultural clash.

Yet there are good grounds for optimism. Above all, Wednesday’s accord amounts to de facto reconciliation of two countries that have fought each other in two world wars at a cost of about 30 million lives, and have continued to be adversaries during the Cold War.

Much of the treaty’s wording, and the exceptionally conciliatory tone of West German Foreign Minister Hans-Dietrich Genscher’s formal declaration, was aimed at easing Soviet concern about a united Germany.

“We want nothing other than to live with all other people in peace and democracy and freedom,” Genscher said, reading a six-page statement that contained other, similar statements.

The Germans went even further, providing Moscow with a letter accompanying the treaty in which they pledge themselves to a free and democratic order, to ban national socialism and to protect Soviet war memorials in Germany from desecration.

In a television statement Wednesday evening, Soviet President Mikhail S. Gorbachev welcomed Genscher’s reassurances that the 360,000 Soviet troops remaining in what is now East Germany will be treated as representatives of a friendly country through the four-year withdrawal period.

As with so many events of the last year, the German-Soviet reconciliation unfolded at a pace few would have believed possible a year ago.

The surprise over Gorbachev’s acceptance of German unity last February was eclipsed only by his agreement a few months later to a united Germany’s membership in the Atlantic Alliance and Wednesday’s final accord.

“It is really an historical change, as much in our policy as for Europe itself,” said Vyacheslav Dashichev, an adviser on German affairs to Soviet Foreign Minister Eduard A. Shevardnadze.

As the treaty creating these realities was signed in a Moscow hotel Wednesday, there was hardly a murmur of public resistance. Muscovites were far too preoccupied by more urgent matters: shortages of food and tobacco, a growing economic crisis.

Indeed, for much of the day, the lead story on Radio Moscow’s news programs dealt not with the gathering of foreign ministers but on plans for economic reform.

Still, it is the urgency of Moscow’s economic needs that heightens the hopes for positive relations with Germany, a country with helpful know-how and, apparently, a willingness to help.

Some help has already been pledged. After tough bargaining over what some called the Soviet price for German unity, the West Germans agreed earlier this week to ease the withdrawal of Soviet forces from Germany to the extent of nearly $8 billion, including the construction of housing in the Soviet Union for returning troops.

A day earlier, West German Agriculture Minister Ignaz Kiechle pledged $600 million in farm products to help with Soviet food shortages. Today the two countries will initial a general treaty for expanding economic, cultural and scientific ties, a treaty that both sides hope will define the new dimensions of German-Soviet cooperation.

The treaty to be signed today “sets the tone and the perspective for the future,” Genscher said.

Germans are likely to be distracted by the demands of reunification, but they view expanded economic and political ties with Moscow as an important element in stabilizing the new European order.

“They (the Soviets) need help, they need to be drawn in,” a senior West German offical observed. “The only question is how best to do it.”