PERESTROIKA New Thinking for Our Country and the World By Mikhail Gorbachev Cornelia & Michael Bessie/Harper & Row

GEORGE KENNAN and Paul Nitze have not often agreed on policy toward the Soviet Union since, between the two of them, they largely shaped the intellectual foundations of "containment" four decades ago. But they were in accord on one point: neither regarded "containment" as a permanent strategy; both acknowledged the possibility that the Soviet Union might evolve in time from a state seeking to challenge the existing international system to one capable of living peacefully within it.

How, though, would one know when the Soviet Union had reached that stage? Are we today sure, after so many years of hostility, that we would even recognize it? General Secretary Mikhail Gorbachev's book, Perestroika (the word literally means "restructuring"), provides an important opportunity for Americans to think about how far the Soviet Union has come since Stalin's day, and what those changes might imply for the future. The fact that the book appears on the eve of the third Reagan-Gorbachev summit makes careful consideration of it all the more vital.

Perestroika results from an invitation the American publishers Cornelia and Michael Bessie extended to Gorbachev shortly after he took power. They asked him to write a "real book," not simply a collection of speeches or propaganda. To their surprise, the general secretary agreed, delivering the manuscript early in September after having presumably worked on it during his conspicuous absence from the public spotlight this summer. The volume is intended as a personal statement of Gorbachev's program: it is not just aimed at an American audience, but has already been published in the Soviet Union and is to appear throughout much of the rest of the world as well.

The book differs in several respects from comparable literary efforts by earlier Soviet leaders. Although often repetitious, it is informal, almost conversational in tone. It is also, in places, very candid: the general secretary quotes with irreverent approval a description of his predecessors as "stone-faced sphinxes"; they were, he tells us, too much given to "grandiloquent twaddle. . . . unwarranted splendor, abstract slogans, and recurrences of pompous ostentation." The first chapter contains what must be the most withering public criticism of the Soviet system ever made by an incumbent Kremlin official: "We only thought that we were in the saddle," Gorbachev concludes, writing of the late 1970s, "while the actual situation was one that Lenin warned against: the automobile was not going where the one at the steering wheel thought it was going."

The reference to Lenin is not casual. Gorbachev invokes the Founder's spirit with an almost religious fervor: he sees his own program as both a return to Leninist principles and an extension of them. Even Lenin acknowledged, he pointedly notes, that a single revolution would be insufficient to transform society: perestroika for Gorbachev is nothing less than a second Russian Revolution, aimed this time at reinvigorating socialism by linking it to democracy. If "democratic processes had developed normally in our country," he admits, "we would have been able to avoid many . . . difficulties. . . . We have learned this lesson of our history well and will never forget it."

But perestroika extends to the realm of world affairs as well. Nuclear weapons, Gorbachev insists, have placed inescapable constraints on the feasibility of class struggle: even "peaceful coexistence" must now be separated -- as Brezhnev was unwilling to do -- from the ultimate determination of one class to prevail over the other. It follows from this that "security" must become multilateral: no single nation can any longer obtain it by making others insecure. Capitalism and socialism will have to exist "within a framework of peaceful competition which necessarily envisages cooperation." History, not class struggle, will decide who wins. WHAT IS one to make of all this? There are, to be sure, ambiguities, evasions and contradictions. Since Marxists have traditionally equated "history" with "class struggle," the distinction Gorbachev makes between the two is not all that clear. Historians can easily show that Lenin's own enthusiasm for democracy was, at best, inconstant. Gorbachev's one-sided explanation of how the Cold War began adds nothing to our understanding of that event: glasnost, it appears, has yet to extend to recent diplomatic history. The difficulty of reconciling democratic principles with what Gorbachev acknowledges will continue to be the absence of an official opposition is an obvious problem. And if nuclear weapons have in fact constrained the class struggle -- and if that is a good thing -- then it is not immediately apparent why the general secretary is so keen to abolish them.

There will also be competing explanations in the West of Gorbachev's motives. "Kremlin-bashers" will treat perestroika as a Subtle Ploy: the crafty Russians are simply pulling the wool over our eyes, they will argue, with the intention of waiting -- for years if necessary -- until complacency has wrecked the defense budget and NATO has gone neutral, at which point they will pop out like some Halloween goblin and frighten us all into abject subservience. Subtle Ploys, after all, can go on for quite a long time: there are still a few people left who think that the Sino-Soviet split is one.

The more serious objection to perestroika will be that its roots are shallow: it represents so thorough a long-term restructuring of Soviet society -- with so few visible short-term benefits -- that it cannot possibly last. The recent Yeltsin affair has emboldened Muscovites themselves publicly to question perestroika's durability; the frequency with which Gorbachev reassures his readers that the Russian people have demonstrated "unreserved and passionate support" for it suggests that he himself may lack complete assurance on that score.

There will also be those in the West who fear that perestroika might actually succeed, and hence make the Soviet Union a more formidable adversary than it is today: from their standpoint, the United States should be doing everything it can to force heavy military expenditures upon the Russians, so that they will be too exhausted to become more efficient.

Gorbachev anticipates and attempts to deal with each of these objections; in doing so he proves himself a keen observer of what Western critics say. But his response in each case boils down to an untestable set of assurances, in essence: "We will make perestroika work. It will pose no threat to you. Trust us." SHOULD WE? Clearly not, at least not on the basis of these assurances alone. But neither should we write off this book as repackaged propoganda. Suppose, for the sake of argument, that Gorbachev really is serious; that perestroika is in fact the long-awaited "mellowing" of Soviet society. Certainly if one had set out at almost any point in the history of the Cold War to describe the kind of Soviet leader we would like to see come to power, the characteristics we would have listed -- intelligence, emotional stability, imagination, accessibility, openness to the outside world, determination to stress domestic reform -- would not have been all that far removed from what we know of Gorbachev himself.

But are we ourselves ready for a Soviet "mellowing," should that prove to be what is taking place? It was only five years ago that President Reagan characterized the Soviet Union as "the focus of evil in the modern world": many took that outburst as evidence that our own domestic system requires the permanent image of an implacable external adversary. The Russians have surprised us now more than once by accepting our own proposals on arms control -- the "double-zero option" on intermediate-range nuclear forces, intrusive on-site verification, the idea of "deep-cuts" in strategic missles -- only to find us agonizing over whether "we really want to do that." Republican presidential candidates rush to disassociate themselves, well in advance, from an I.N.F. treaty their own president has negotiated, one that removes more than three Soviet warheads for every American warhead dismantled. And most recently it has become clear that the Congress of the United States, like an unruly child, lacks confidence in its own capacity to behave politely if the general secretary should come before it.

Not the least value of this important book could be the way it might force us to look more critically at ourselves: to ask whether we would be prepared to recognize and respond to the changes in the Soviet Union we have claimed to want for so many years, if in fact they are occurring. The Russians, after all, have no monopoly on intellectual rigidity, bureaucratic ossification, and lack of imagination in high places: "old thinking" has afflicted both sides quite impartially in the Cold War. A little perestroika of our own may be required. ::

John Lewis Gaddis teaches history at Ohio University and is the author of the recently-published "The Long Peace: Inquiries Into the History of the Cold War."