Why the Superpowers Could Both Decline : THE RISE AND FALL OF THE GREAT POWERS Economic Change and Military Conflict from 1500-2000 <i> by Paul Kennedy (Random House: $24.95; 480 pp., maps and charts) </i>

Paul Kennedy, Dilworth Professor at Yale, has written or edited several books in the fields of diplomatic, military and naval history. In the present work, he sets out to explain, in a survey, the rise and fall of the various great powers in the world over the last five centuries.

The theme underlying his analysis is that economic and technological developments determine the military power of individual states and empires. When these developments alter significantly, one great power will decline in strength, and its place will be taken by another, by a power capable of exploiting the new conditions more efficiently than its rivals.

As Kennedy admits at the end of his book, the argument that economic growth can have a crucial effect upon relative military power is “unsurprising, and has been said many times before.” Indeed, one wonders why Kennedy has written the first part of this book at all. It is based upon exhaustive reading in a very wide range of literature, but he trots out one familiar historical platitude after another to explain and account for the great power alterations in his story.

This first part of the book is little more than a college textbook. It is at a higher level than most textbooks, but it is in that category that it belongs, and in no other. One also wonders why Kennedy, in his introduction, chooses to compare himself with the great Prussian historian, Leopold von Ranke, who has been compared to Sophocles and Goethe.

However, in the latter part of the book, Kennedy abandons his historical account in order to present us with a powerful, brilliant, and well-informed analysis of the five great powers in the world that today compete for the future mastery of our planet. This analysis differs entirely from what has gone before and is really another and more impressive book. It is a fascinating exposition of the status now enjoyed by China, Japan, Europe (the European Economic Community), the Soviet Union and the United States. In addition, Kennedy offers us his predictions about the future of these great nation states.

Kennedy deals with the Asian countries first. He explains that China, the poorest of the great powers, is working out a grand strategy entirely more coherent than any of its rivals. He expects that this strategy will transform the country in a few decades. China has employed massive resources in order to create a “green revolution” that will solve its food-supply problems. The drive toward industrialization is even more intense. Above all else, the armed forces are not allowed to consume resources needed elsewhere. This is in stark contrast to Soviet policy and also to that of the Reagan Administration.

With respect to Japan, Kennedy argues that that country will expand more quickly in the future than the other powers. State direction of industry there has proved more effective than the uncoordinated laissez-faire approach of the United States. Japan devotes huge sums to industrial research and, owing to U.S. policy, its defense expenditures are kept to a minimum.

The future for Europe, the EEC, is less bright in Kennedy’s opinion. The Europeans, he argues, spend too much on defense and are weighed down by extensive strategical commitments.

The Soviet Union, according to Kennedy’s analysis, needs more agricultural and industrial output. However, it continues to hobble enterprise by collectivization and heavy-handed planning. The party elite stifles individual initiative, and this has a deplorable effect in high technology, which is already flowering in Japan and California. He stresses that too great a share of the country’s resources are devoted to the armed forces. The engineering and scientific energy devoted to the military is not employed in robotics or other high-technology enterprises. The use of computers, a necessity for the future, challenges the intensely secretive, bureaucratic and centralized Soviet system. Without its massive military power, Kennedy explains, the Soviet Union counts for little in the world; but in order to maintain so gigantic a force, the Soviets must damage their own economic future.

According to Kennedy, the problems of the United States are not as great as those confronting the Soviets. The task of American leadership is to preserve a reasonable balance between the nation’s defense requirements and the means it possesses to maintain its commitments in every part of the globe. The United States, he says, now runs the risk of “imperial overstretch.” Today it has the same international obligations it had a quarter of a century ago when its share of the world’s Gross National Product was much larger than it is now. The decline in certain American key industries must have a doleful effect upon its ability to wage a conventional war. The Americans, and other great powers also, Kennedy concludes in an epilogue, are “like an old man attempting to work beyond his natural strength.”