As sometimes happens in world affairs, perhaps the most important event of recent days was one that did not happen. President Reagan did not publicly accuse the Soviets of violating the SALT II agreements. Instead of making a big public affair about recent Soviet testings of nuclear devices, tests which may involve violations, he allowed the State Department to use the diplomatic machinery set up under SALT and other agreements for handling just such matters - quietly.
The effect of handling doubts about Soviet action diplomatically instead of in the propaganda arena is to keep the channels open for negotiations with the Soviets both about the big intercontinental weapons and the medium-range ones in Europe.
The propaganda approach is favored and was being urged on the President by those in Washington who oppose serious negotiations at this time. Their preference is for a weapons-building program first - then perhaps holding talks much later when, in theory, the United States might have an advantage in the latest weaponry - and hence a stronger bargaining position.
Also, going public with charges of Soviet violations might in theory counteract the nuclear freeze movement and reduce the possibility of a pro-freeze vote in the House of Representatives.
The non-event may be of short duration. The President can change his mind and go public any time he is so inclined. The pressure on him from the Pentagon and right-wing politicians will undoubtedly continue.
But the non-event of the moment does register the fact that the ''pragmatists'' in the circle of White House advisers are active, have influence , and in this case won one round against the ideologues.
It is not the first win for the ''pragmatists.'' In domestic affairs the compromise on social security legislation was a major victory for the moderates.
Moderation seems to be gaining over the radicals in both foreign and domestic affairs. It has showed up of recent days in congressional cuts in the arms budget.
It showed up again during the past week in a compromise over Central American policy. The President agreed to appoint a special ambassador who is to search for a negotiated end to civil war in El Salvador.
In return Congress reluctantly let Mr. Reagan have some of the money he wanted for guns for the present regime in El Salvador. But in order to get the money the President had to agree to keep the channels open for a possible nonmilitary solution in Central America.
The moderates have not yet weaned the President away from his desire to wage an economic cold war against the Soviets. A meeting was held during the past week in Paris to try to work out a common policy on East-West trade for use at the next economic ''summit'' conference to be held in Williamsburg, Va., at the end of May.
Agreement was not reached at the Paris meeting. It broke down once more, as it broke down at the Versailles economic summit. The Reagan administration is still seeking much tougher restraints on East-West trade than the European allies are willing to accept.
The practical effect is that the existing condition continues. The European allies and Japan will not be coerced into a trade war they regard as being contrary to their own best interests. Besides, Mr. Reagan did not help his case for such a trade war by authorizing his own negotiators to try for a bigger guaranteed share of the Soviet grain market.
But in the matter of nuclear arms Mr. Reagan is deferring to the wishes of his European allies and Japan rather than to the wishes of the hard-liners in his own political family.
The SALT II treaty is, of course, not legally binding on anyone because it has never been ratified by the US Senate. However, both Moscow and Washington have declared their intention to observe its terms, and so far claim to be in a state of observance. The Soviets have apparently pushed to the extreme outer limits of the terms and may have crossed the line. As the President said in a press conference, there is ambiguity in the terms.
A public shouting match over whether the Soviets have crossed the line would have the net effect of delaying and complicating the next round of talks looking toward new controls and limits on nuclear weapons. To negotiate over the question of possible violations would in itself be a phase in working toward new agreements.
Meanwhile, it was noteworthy that the Swedish government has told the Soviets that they would shoot the next time Soviet submarines enter Swedish waters without permission. This follows a veritable wave of expulsions of Soviet spies from all over Western Europe as well as Australia and the US.
There is something new in the posture of the West Europeans toward Moscow. Firmness seems to have replaced tenderness. They toss out Soviet spies quite unceremoniously and without apparent concern for consequences.
In a recent speech Britain's former foreign minister, Lord Carrington, said that ''Moscow is already a decaying Byzantium.'' European governments are behaving toward Moscow in these days like people who think Lord Carrington is correct.