Washington — Harsh verbal duels and propaganda aside, the two superpowers are still showing signs of pragmatism in both words and actions. The moderate tone of President Reagan's speech Thursday on the subject of East-West relations and arms control underlined this.
The President called on the Soviets to vie with the United States ''in the realm of ideas, on the field of peaceful competition.''
''Let history record that we tested our theories through human experience, not that we destroyed ourselves in the name of vindicating our way of life,'' Mr. Reagan said. ''And let us practice restraint in our international conduct, so that the present climate of mistrust can someday give way to mutual confidence and a secure peace.''
Reagan alluded in the speech, however, to one issue that could inject new tension into the US-Soviet relationship. He said that the il6l,0,10l,9pSoviets had shown resistance to the idea of significant reductions in nuclear arms and to measures of effective verification of arms control agreements. And promising to disclose more in the near future, he charged that there have been ''increasingly serious grounds'' for questioning the Soviets' compliance with arms control agreements that have already been signed.
An administration official said that the President was referring here to Soviet unwillingness to ''upgrade verification procedures'' and to reports that the Soviets have tested two new missile types in possible violation of the SALT II agreements. The US and Soviet Union have signed the SALT II agreements, but the US Senate has never ratified them. The Reagan administration has said that it will do nothing to undercut the agreements. The National Security Council staff is close to making its determination as to whether SALT II has indeed been violated.
The President's speech to the World Affairs Council in Los Angeles also called on America's allies to adopt comprehensive safeguards designed to prevent the spread of nuclear weapons technology. Reagan said that in the days ahead he would be talking with other world leaders about the need for ''urgent movement'' on safeguards and on other measures.
It was the strongest statement that the Reagan administration has made to date on the subject of nuclear proliferation. The President's call appeared to be directed at Britain, West Germany, France, Italy, and Japan. An administration official said that Reagan had grown concerned about ''an accumulation of trends which is very worrisome,'' including ''trends in Southwest Asia.'' This was an apparent reference to reports that Pakistan is developing a nuclear weapons capability.
Congressional critics have accused the Reagan administration of being too slow to recognize the seriousness of nuclear weapons capabilities spreading beyond the current nuclear ''Club of Six.'' But when it came to nuclear proliferation, as well as East-West relations, the President's Los Angeles speech was in many ways one which could have been made by several of his predecessors.
Reagan did not describe the Soviets in quite the same harsh tones he used in his March 8 speech to the National Association of Evangelicals, when he described the Soviet Union as ''an evil empire.'' But in the Los Angeles speech the President did declare that American moral values and basic rights were being ''fundamentally challenged by a powerful adversary which does not wish these values to survive.'' The President repeated his charge that the Soviet Union has engaged in a ''relentless military buildup, . . . acquiring what can only be considered an offensive military capability.''
Reagan also delivered a stinging criticism of calls for a nuclear freeze. The speech could thus be viewed as a mixture of the ''tough'' Reagan as well as the ''nice'' Reagan. It was Reagan showing his tough side in some recent statements, such as the March 8 speech, and equally harsh declarations from Soviet leader Yuri Andropov, which convinced some observers that the US and the Soviet Union were sliding toward a new cold war. But two veteran Sovietologists who have negotiated with the Soviets noted that in their actions, and even in some of their words, the two superpowers are far from a cold war, much less a direct confrontation.
Helmut Sonnenfeldt of the Brookings Institution, former right-hand man to Henry Kissinger at the State Department, noted that even in the midst of three major conflicts that have occurred since the Reagan administration came to power - the Falklands, Lebanon, and Iran-Iraq wars - the two superpowers have exercised caution.
William G. Hyland of the Carnegie Endowment for International Peace, a former deputy national-security adviser with the Ford and Nixon administrations, agrees with Mr. Sonnenfeldt. Both experts warn, however, that the Soviets' placement of SAM-5 missiles in Syria is worrisome. But they see these signs of pragmatism from the Soviets: their agreement to an early return to the Geneva talks on intermediate-range missiles and their reluctance to dismiss the latest US proposal.