The Kremlin has taken the unusual step of warning President Carter that, unless he curbs the hawks within his own administration, the arms-limitation talks could be wrecked, and that "can have only one outcome: a sharp increase in the danger of a nuclear missile catastrophe."

On the face of it, Pravda is concerned at the lack of progress in the strategic arms limitation talks, at the slowness of the negotiations, at the emergence of new U.S. demands that, it claims, go beyond the previous more moderate U.S. positions. At no point does Pravda expressly blame the administration for this supposed change. Indeed, it notes that Carter has stressed repeatedly the importance of reaching a new agreement, and that this gave a strong impetus to the negotiations.

So far, so good. But that, is says, is not to the liking of those forces "that want to retard and even to wreck altogether" the SALT accords, and are making SALT the focus of an acute political struggle in the United States. It trots out the traditional list of cold-warriors, from the Pentagon and the Committee on the Present Danger to the military-industrial complex, but those "open opponents" seems to cause it less concern than the hidden adversaries whom it evidently regards as far more dangerous.

Pravda speaks of unidentified figures "who do not appear to oppose an agreement directly, but who in fact strive by every means to erect more and more obstacles on the path to its conclusion." They claim they only want to improve the treaty, but when the government fails to do as they say, they "cast off their masks" and accuse it of being too soft and compliant in its dealings with Moscow.

But its Pravda speaking only of the traditional cold-warriors outside the administration? To those prepared to read between the lines, another message becomes evident. What Pravda is saying, at this deeper level, is that some of Carter's advisers are as bad as the outside cold-warriors - such as Zbigniew Brzezinski, the president's national security adviser. Apart from Defense Secretary Harold Brown, who as the Pentagon's top official is by definition a black beast in the Soviet view, Brzezinski is the administration's member attacked most frequently - and, indeed more sharply than Brown - because he is perceived by the Kremlin as acting as Cartet's evil spirit.

Some of the detailed and specific objections that Pravda raises against present U.S. attitudes on SALT can be traced to Brzezinksi's earlier views on arms-limitation issues. Pravda does not name him, as did when it sniped at him on lesser matters, because in this context it would be impolitic to do so. But Soviet officials appear to work on the assumption that in the determination of SALT policy, Brzezinksi is the hard-liner - whatever Washington detractors (who regard him as blowing hot and cold, depending on the president's mood) may say.

At the other end of the spectrum Soviet officials see Paul Warnke, the chief SALT negotiator and head of the Arms Control and Disarmament Agency, whom they regard as a moderate. In this the Washington view concurs with theirs, and both are right. The Russians have also found him a tough negotiator, with a nimble lawyer's mind, who can drive a coach-and-four through a poorly constructed argument - but who can also seize a tiny opening and enlarge it sufficiently to give a new impetus to negotiations.

In the middle they see Secretary of State Cyrus Vance, who indeed acts as something of a middleman, though perhaps with a slight inclination to favor Warnke's views over Brzenzinski's, at least on arms-control matters. For all their ritual attacks on the Pentagon's Brown, the Russians seem somewhat puzzled by the man who, on the one hand, presides over the biggest U.S. military budget in history, while on the other hand is making a more determined effort to curb the appetites of the military than any secretary of defense since Robert McNamara.

In the end, to their surprise, the Russians came to regard McNamara as a dove - but by then it was too late, and he was on his way out of the Pentagon. Brown is no more a dove than McNamara was at first - but he isn't a hawk either. It is in the Kremlin's power, by its reaction to his policies, to push him in one direction or the other.

For all Pravda's careful wording and its failure to discuss directly the attitudes of the key administration figures, this is really the issue to which it addresses itself between the lines. It is warning the administration in effect that the Kremlin can be pushed only thus far and no farther on the various SALT issues in dispute, and it is telling Carter that, if he listens to Brzezinski rather than to Warnke, the arms-limitation agreement might come to grief. But if that is the Kremlin's message, it may also have one effect that Moscow did not intend.

By showing Carter how concerned it is about Brzezinski's views, it may persuade the president that his national security adviser is a good man to have around for more reasons than all the obvious ones. If Brzenzinksi is the hard-liner that the Russians take him to be, and if he has the influence on the president that they suspect he has, then the diplomatic and strategic game is played for higher stakes than it otherwise would be. In a game for higher stakes the United States, with the greater resources behind it, is the more likely winner - so long as the game is kept to conventional stakes, and stays away from the nuclear ones.