US-Soviets envision future pacts with more punch. Proposal in hand would give Gorbachev more leverage at home and abroad. Moscow, Washington, and Europe see the proposed arms pact as lubricant for improved superpower relations. Gorbachev has gained breathing room for his reform policies. Both the Soviets and the US have shown greater flexibility. And European concerns of being abandoned by the US have been largely allayed.

If signed, an agreement on intermediate-range nuclear forces (INF) should give Mikhail Gorbachev a boost at home and abroad. It will provide a tangible success that has so far escaped him. It will help prove to skeptics in the leadership the feasibility of his vision of a new framework for East-West relations and security policy. And, if the INF treaty provides impetus for a series of arms reduction pacts, it will go a long way toward achieving one of Gorbachev's main aims: lowering the threshold - and with it, he hopes, the dangers and the costs - of East-West military confrontation.

Despite an improved image abroad and a more open atmosphere at home, Gorbachev has not yet been able to point to a major political success. One other prospective victory, record harvests, is gravely threatened by bad weather. His economic reforms have yet to bite, and when they do, are likely to be painful at first.

Gorbachev probably needs a substantive achievement as much as anything to convince some of the skeptics in the Soviet leadership. In his two years in power, he has proven himself a risk taker. He has staked much prestige on his proclamation of the need for an ``all embracing'' restructuring of security policy in a nuclear world. He has emphasized the need for the reduction and eventual elimination of nuclear weaponry.

Meanwhile Western observers speculate that some Communist Party leaders feared that the risks tied to Gorbachev's policies were too high. As one Western ambassador said: ``Some of the old guard [leaders] seem to feel that the world is too dangerous a place'' for a Soviet leader to attempt radical economic and political reform.

Two of the country's most senior leaders have voiced concern at increased threat from the West in recent speeches.

An INF pact, especially if it was accompanied by a general relaxation in East-West tensions, could finally provide reform backers with the proof that the risks do not outweigh the advantages. Progress in arms control would also bolster Gorbachev's theory of United States-Soviet interdependence, which stresses political cooperation and ideological competition over military confrontation.

Instead of trying to export revolution - a ``senseless and dangerous'' approach in the modern world - Gorbachev supporters say the Soviet Union should try to compete with the West by force of example. In the latest edition of the theoretical journal Communist, one of Gorbachev's main foreign policy advisers, Yevgeny Primakov, stressed that Moscow should create a system whose ``economic and political system and democratization ... is on a higher level than anything capitalism currently offers or can ever offer.''

Mr. Primakov noted that Soviet prestige had grown in the West. This, he said, was the result of the leadership's willingness to admit mistakes and undertake a ``broad democratization'' of Soviet society. Moscow's vastly improved public-relations machine will undoubtedly try to capitalize on the latest agreement - hammering home the new leadership's flexibility in accepting a pact that a few years ago was described by some Western experts as unattainable.

Finally, an INF agreement will probably save Moscow money. Gorbachev and his supporters are committed to a policy of ``reasonable sufficiency'' in defense. This admits that military expenditures are an important impediment to economic development, and calls for them to be kept to the minimum necessary to preserve security. It also stresses the primacy of civilian political leaders over military in formulating defense policy.

How big the savings will be is unclear: The nuclear weapons to be destroyed cost a huge amount of money, but represent only a small proportion of their overall arsenal. Most important is that Soviet leaders clearly hope that INF is only the beginning of a trend toward much more significant arms control agreements.