A REVIEWER should disclose his prejudice. Mine is

that the late Harold Nicolson left the definitive model for writing about diplomacy in his little book, The Evolution of Diplomatic Method. It combined history, ancedote and urbane judgment, all in pleasing proportions.

Gordon Craig, co-author of Force and Statecraft, is a writer of Harold Nicolson's class and urbanity and the historical sections of his book show it.

Indeed, both these books are in a sense footnotes to Nicolson. Force and Statecraft traces the search for a system of equilibrium among nations from the rise of the modern state to the present. Diplomacy, though it is otherwise stingy with examples, contains a masterly survey (chapter seven) of diplomatic history.

Both books largely share Nicolson's bias, if not his unabashed nostalgia, for what used to be called the "old diplomacy," that is, the cozy 19th-century arrangements for peacekeeping that flowed from the Congress of Vienna. Craig and George throughout, and Watson by fits and starts, seem to share Nicolson's view that international society has failed to improve on the "Concert of Europe," or to find in more visionary international arrangements a lasting substitute for it.

As might be expected, Craig and George are quite critical of Woodrow Wilson, the American president who injected new ideals ("open convenants openly arrived at"; "not a balance of power but a community of power") into diplomacy during World War I. Wilson, they observe, "was less a historian than a visionary, inspired by a conviction . . . that relations of the peoples of the world should be regulated not by the outworn standards of Europe, but by democratic principles."

They are for similar reasons dismissively critical of Wilson's distant political heir, Jimmy Carter. They write that Carter's reaction to the Soviet invasion of Afghanistan in late 1980 was "intemperate and ill-considered," although they do not suggest that he could or should have let the incident pass without murmur.

Adam Watson, who has held various posts as a British diplomat and is now associated with the University of Virginia, also pays his dues to the virtues of the old diplomacy. He notices how durable many of its forms have continued to be, down to the present. But it is among his principal arguments that the recent era--marked by military stalemate between the superpowers, the proliferation of new states, the centralization of power, and economic interdependence--calls for new wrinkles in diplomatic method.

History has been called "philosophy teaching by example," and both these books bring the maxim to mind. If there is wisdom to be gained from the history of diplomacy it unfolds in example.

But I judge from both these books that writers on diplomacy are of two minds about how much historic examples can teach. Watson's Diplomacy, laboriously explanatory, walks a narrow path between subtlety and banality, sometimes teetering toward the latter. For example, he takes a whole chapter to establish "that states or political entities which wish to retain their independence . . . are fated to communicate with other states and unions outside their own," a point that sophisticated readers may assume to be self-evident to begin with.

In the second part of Force and Statecraft there is a similar tendency to labor the obvious, in the name not of history but of the academic discipline of "international relations." That discipline, to be distinguished from plain old diplomatic history, is a quest for a systematic taxonomy of principles and axioms. Thus Craig and George, in part two, seek to elicit general lessons from case studies. But the case studies, prepared initially by their graduate students, are brief and sometimes shallow. And the general principles are couched in jargonistic language and illustrated by diagrams whose value is hard to grasp.

Adam Watson, for all his plodding, never stoops to poli-sci gobbledygook. That cannot be said, alas, of Craig and George, who commit such gems as "operationalization" (i.e., "putting into practice"?), prompting the suspicion that Secretary Haig might have taken an inspirational hand in the writing.

"Coercive diplomacy," say the authors of Force and Statecraft, is "context-dependent," meaning that "careful consideration must always be given to circumstances." But if so, the attempt to be schematic may be riskier than they acknowledge.

But I quibble too much. The virtues of both these books outweigh their flaws. There is wisdom and information in both. Both make strong cases for realism and historical awareness in the ordering of diplomatic relations. Neither resolves, though both consider, the eternal dilemma of the place of force in diplomacy. Both take it for granted that force, used or threatened, will remain a factor for the foreseeable future.

As Watson reminds us, war was once called the ultima ratio regum--the last argument of kings. It is still, often, the last argument of nations, though most of the kings are gone.