WRITING about the U.S.S.R. today is like juggling. The adept Sovietologist is one who can reckon with the most numerous and diverse factors without dropping any from sight. It is subtle work, and most of the difficulty is lost on the general public, which prefers those writers who take flashy short cuts. Pentagon hawks and the more starry-eyed peaceniks have this in common, for both do superficially impressive performances by limiting their acts to a few simple elements. They avoid what is uncomfortable to handle. What they do looks simple because it is simple.

Seweryn Bialer, director of the Research Institute for International Change at Columbia, does not take this easy path. In his new study of the Soviet Union he brings into play a stunning array of data. Economics, intra-party politics, foreign trade, Third World relations, and national history are but a few of the fields he invokes. It is an important book, both because it assembles state-of-the-art insights on the Soviet system as a whole and, more significant, because it addresses directly the urgent question of how domestic and international concerns interact in Gorbachev's Russia.

Bialer's title contains his thesis: that Gorbachev faces grave troubles at home that cannot be resolved without changing the system, but that his administration is unwilling to do this for fear of undermining the Soviet "empire" in Eastern Europe and of limiting its power to intervene further afield. In other words, the demands of an active foreign policy take precedence over thoroughgoing domestic reform, Gorbachev's own assertions to the contrary notwithstanding. He devotes half the book to fleshing out the international dimension of this thesis.

It has often been claimed that the Soviet Union has become a status quo power, its main global interest being to preserve the gains it has achieved in recent decades. Bialer ruthlessly criticizes the "American liberal establishment" for this notion, arguing instead that Kremlin leaders remain committed to the support of violent change, revolution, civil war, and regional military conflict. America's task is to curb Soviet expansionism.

And here the juggling begins. Having advanced this rather hawkish view of Soviet intentions, Bialer then follows up with some eminently moderate advice for Washington. It is true, he argues, that detente favored the Soviet Union and that it fostered "false illusions" in the American public. The alternative is not confrontation, however, but a policy that would "regulate" conflict through a process that Bialer terms "competitive coexistence" or "managed rivalry." This means avoiding nuclear war, of course, but it also means resisting the temptation to goad the Russians. A mood of confrontation will backfire, Bialer claims, for it will cause Soviet citizens to rally around a regime that cannot otherwise gain legitimacy through performance. Strict controls on technology exports to the U.S.S.R. are likely to have a greater impact now than a decade ago, but the U.S. should be ready to shelve the Strategic Defense Initiative if the Russians would limit their offensive weapons.

Having presented the U.S.S.R. as hostile to the status quo worldwide, Bialer then shows how deeply committed it is to maintaining its position in Eastern Europe. Why else, he argues, would Moscow bail out the Polish economy under Jaruzelski? Bialer asserts that the Kremlin, in order to preserve its position in Eastern Europe, fosters political orthodoxy there rather than reform, and economic stability rather than development. Never mind that Hungarians have managed to carve out some breathing space for themselves, and that the Polish government may be trying to do the same. The logic of empire in the Kremlin will prevent these currents from flowing very far. And if they are unacceptable in Eastern Europe, are they not yet more dangerous at home?

In this way, Bialer argues, the demands of empire constrain domestic reform in the U.S.S.R.. He acknowledges that there are other forces inhibiting basic change, notably the absence of a generally accepted program of reform and Gorbachev's apparent belief that the system itself is basically sound but needs to be stimulated through what American labor would term a "speed up." The heart of Bialer's thesis, though, is that the regime is addicted to an expansionist foreign policy and to the military program needed to undergird it. Domestic reform is impossible without cutting back funds for the military. Even without the perceived threat from the Reagan administration, Bialer concludes, the military factor would provide a "rationale against fundamental reforms." AGAINST all this, Bialer presents his case for why basic economic reform is essential. The crisis of the economy can only be resolved by changing the system, presumably by allowing decentralization and the freer play of market forces. Until this occurs, he claims, the U.S.S.R. will continue to suffer from a "crisis of effectiveness." Lags in productivity and the rise of mass apathy will eventually threaten the stability of the social order. Increasingly, Bialer predicts, "the political instruments of power will have to be applied with greater weight."

Urgently needed domestic reforms thwarted by grandiose international aspirations -- this is the heart of the "Soviet paradox" as Bialer sees it. Stated thus, it all seems quite simple. To Bialer's great credit, he advances this argument even while presenting evidence that suggests that the situation may be more complex and nuanced. He is juggling hard, and his book is the richer for it.

Will Gorbachev be able to cut the Gordian knot that ties domestic policy to foreign ambitions? Since the answer is unknowable for now, let us ask instead whether this "Soviet paradox" is quite the way Bialer describes it. In this reviewer's judgment it is a useful construct but overstated in both its foreign and domestic dimensions. The Kremlin's military budget is huge by any measure. But as CIA data now confirm, the rate of growth has been kept in check for a number of years. The Red Army is locked in a major war in Afghanistan, but that war dominates Soviet domestic affairs to a far lesser extent than Vietnam shaped the American home front in the Johnson and Nixon eras.

Regarding domestic renewal, Bialer minimizes tha gains that the Andropov-Gorbachev reforms have already achieved. Granted that the program shows no appreciation for what is happening in Budapest or Beijing, and that it leaves intact all of the main pillars of Stalinism, including centralized planning. Nonetheless, tens of thousands of managers are being transferred out of unproductive firms and agencies, the middle levels of sprawling ministries are being thinned, and a degree of devolution introduced. This is no revolution but it could at least thwart the decline that has vexed Soviet leaders for years.

Along with these organizational changes, Soviet society is evolving in reformist directions through a momentum of its own. The old Stalinists are dying out, and their replacements are better educated, less insecure, and less dogmatic. The information revolution is proceeding slowly but it is occurring nonetheless, and is making headway against the entrenched secretiveness of official life in Russia.

In his advocacy of revolutionary change in the U.S.S.R., Bialer understates the amount of evolutionary change that is actually taking place there. These are not good times in Mother Russia, but it is simply inaccurate to say that "the cycle of revitalization in Russian history inaugurated by the Soviet seizure of power has exhausted its domestic potential." The productivity of Soviet labor may be abysmal, but can one speak of the "profound disillusionment of the working class"? What does it really mean to declare that "Soviet youth is cynical and career-minded," or that "the professional class is on the whole both materialistic and preoccupied with professional concerns"? Sound familiar? And again, does the Russian tradition truly "foster an aversion to risk-taking," and is her history really characterized by "periods of mass apathy . . . regularly interrupted by outbursts by mass violence"? Finally, how can one contend that "Russia's enormous economic potential has never been realized to any significant degree" when its rate of development has roughly paralleled, for example, that of Italy? At times the Polish-born Bialer is downright petulant about the Russians, to the point of griping about arrogant flight attendants and hard seats on Aeroflot, the People Express of the U.S.S.R.

In fairness, it should be stated that such outbursts are rare in The Soviet Paradox. However, the deep pessimism about Russian society reflected in them lies at the bottom of Bialer's argument, causing him to dwell more on the darkest forces of continuity than the brighter forces of change.

Happily, he provides readers with an antidote to his own gloom, in the form of timely warnings against "worst case analyses" and against the various apocalyptic views of Soviet development, both international and domestic, that are common among Sovietological pundits. In short, Bialer keeps juggling to the end, thanks to which his grateful readers will do so as well.