Do Soviets violate arms pacts? Long-awaited report ready

After months of study and debate, top-level officials are about to present a report to President Reagan on possible Soviet violations of nuclear arms control treaties.

Conservatives in Congress have been pressing the administration to go public with such a report, in part apparently because they believe it will show that the Soviets lack the goodwill needed to conclude effective arms control agreements.

Kenneth L. Adelman, director of the United States Arms Control and Disarmament Agency (ACDA) said Tuesday that the new report on possible violations would be presented to the President ''soon.'' The report will go to Congress either when it reconvenes Jan. 23, or shortly thereafter, he said.

The administration has already taken the issue of possible treaty violations to a special US-Soviet committee in Geneva, the Standing Consultative Commission (SCC). But Soviet responses to American queries made within the SCC were reported to have been unsatisfactory.

The most prominently mentioned possible Soviet violations include testing of what some US officials consider to be two new types of land-based ballistic missiles, the encoding of radio signals beamed to earth during Soviet missile tests, and the construction of a huge new Soviet radar installation in south-central Siberia. The Soviets reportedly contend that the radar is designed to monitor space flights and is not part of an antiballistic missile system.

A debate has raged within the administration for many months over the seriousness of possible Soviet violations. Last March in Los Angeles, Reagan said there were ''increasingly serious grounds'' for questioning Soviet compliance with existing arms control agreements.

Over the past three months, top-level interagency study of possible Soviet violations has intensified, with the ACDA doing much of the evaluation. That study is headed by Robert C. McFarlane, the President's national-security adviser.

In March, President Reagan said he would say more about Soviet compliance in the near future. But the administration has been constrained from publicizing its findings for political and technical reasons.

Among the political problems is the possible public impression that the US is hardening its attitude toward the Soviets just as doubt grows in Western Europe and elsewhere over whether US-Soviet arms control talks will continue. Since the Soviets walked out of the talks on intermediate-range missiles, and with doubt now cast over the future of the strategic arms talks, the administration is under heavy pressure from its European allies to show it is serious about arms control. The escalation of combat in Lebanon has added to fears about US-Soviet tensions.

Publication of the interagency report on possible violations could prove awkward for Reagan in yet another way. It might cause critics to point to two developments that could eventually result in US violations of arms control agreements: possible deployment of the MX missile and development of an antiballistic missile defense.

It might prove awkward, too, for the administration to point to possible Soviet cheating on an agreement, the SALT II treaty, which the US previously repudiated and which the Senate never ratified. The Reagan administration has said that it would not undercut that treaty as long as the Soviets agreed not to violate it.

At a Tuesday breakfast meeting with reporters, ACDA director Adelman was asked whether the release of the nearly complete report on possible Soviet violations would damage chances for conclusion of an arms control agreement. It has been suggested that the report was more or less complete months ago, but that the administration has deliberately held up its release.

This ''is not in a 'hold' situation at all,'' Adelman said. ''These are very difficult topics, and they require a lot of work.''

He gave the following reasons for why the task of determining violations is so difficult:

* There is always doubt about what the treaty wording actually means.

* Unilateral statements from both sides on what has been agreed to complicate the picture.

* Questions can arise over the quality of the intelligence which is acquired on possible violations.

* Contradictory information may further complicate the picture.

* Soviet responses to American charges on violations must be taken into account.

''From these you come to some kind of judgment, but it's not always apparent what kind of judgment,'' said Adelman.

Would charges of possible violations disrupt arms control? ''The answer is no. We have been talking to the Soviets in the SCC and at very high political levels about these issues. The Soviets know our concerns.''