After Brezhnev? A White House aide, Norman Bailey, took a crude cut at the question Wednesday, speculating in public on who might and might not "be perceived as threatening to other members of the Politburo." The day before, Secretary of State Alexander Haig had taken a sensible cut, staying a respectful distance from personalities while indicating the American interest in how the Kremlin transition comes out.

Haig observed that the succession 1) may extend over the decade, 2) comes as the Kremlin experiences growing economic strains and international isolation and 3) offers the United States an opportunity to show by its policies that we will penalize aggression but reward restraint.

This approach shows welcome balance. It is unprovocative and certainly it beats the hard-line fantasy that Moscow's wobbles and woes offer Washington the chance to gun defense spending and foreign policy and to go permanently one up on Moscow.

Haig edged right up to the question that preoccupies Kremlinologists as they watch the sun set on the Brezhnev regime. Has Brezhnev, by his consensus-hugging conservatism, brought the Soviet Union to such internal, other-than-military debility that a sharp change is unavoidable?

The 18-year Brezhnev era, I might note, has been a washout for Kremlinologists. Bored to tears, many in government, academia and elsewhere have drifted off. Journalist Victor Zorza, for example, once a sharp needle in the analytical community's side, now writes from a village in India. The best analyst in Washington sniffs that Brezhnev's characteristic regularity and collegiality have dulled the openness of American policy-makers to the fine analyses that are the Kremlinologists' stock in trade.

Broadly, there are two schools of Kremlinology, each with a certain political tinge. The more conservative school follows after the late Merle Fainsod of Harvard. He thought to understand Soviet politics from the top down, and he looked to see who managed the principal institutions, like the party, army or police, or, by extension, the principal ideas, like Communist ideology or Russian nationalism. A leading disciple of this "totalitarian model" is the National Security Council's Richard Pipes.

The other, more liberal school sees (often esoteric) evidence in Soviet print of a tentative interest-group pluralism whose "power struggles," if they took place in America, would be called politics. Jerry Hough of Duke and Brookings argues this "conflict model."

The Washington outlook represents a mix of the two schools. The basic view now holds that the Soviet system is in crisis. Even as Haig, speaking for the establishment, talked of the Soviet system's frailties, I was hearing from outsider Hough that: the Brezhnev generation, children of the Soviet military-industrial complex, is passing. The windfalls of the postwar baby boom and the big oil and gold exports are over. The Soviet bloc cannot conceivably match the last decade's $80 billion relief in Western credits. Ergo, reform is the only way out.

What differences there are among the analysts go less to analysis than prediction: is the window being opened by reform pressure one of opportunity or danger? Some figure the Soviet Union will be pulled more or less to Hungarian-style economic reform. Others fear a slide to a military dictatorship. Generally, reform and a more moderate foreign policy are teamed, and that is where Haig's modest notion of influencing the Kremlin outcome by penalizing aggression and rewarding restraint comes in.

How interesting, you say, but who's coming out on top? I offer you a former Moscow correspondent's caution:

On a nasty, cold spring day in 1965, we correspondents were out on the tarmac to welcome Nasser, idly counting the portraits of Politburo members that soldiers bore on poles. There was a sudden buzz: one Politburo portrait was missing! Sugarplums of "Kremlin shakeout," "power struggle," "purge" danced in our heads. But then the crowd parted and through the red sea, chased by a gesticulating officer, scurried a gloveless soldier bearing-- you guessed it--the missing portrait.

So much for predicting who's next in the Kremlin. A prudent person would sooner bet on the Kentucky Derby. struggle," "purge" danced in our heads. But then the crowd parted and through the red sea, chased by a gesticulating officer, scurried a gloveless soldier bearing-- you guessed it--the missing portrait.

So much for predicting who's next in the Kremlin. A prudent person would sooner bet on the Kentucky Derby.