CENTRAL AMERICA: THE REAL STAKES by Lester D. Langley (Crown: $15.95; 248 pp.) : INSIDE CENTRAL AMERICA by Phillip Berryman (Pantheon: $5.95; 142 pp.)

On great and complex issues, the first book to read can be the most difficult to find. The Reagan Administration’s burgeoning involvement in the crises of Central America has unleashed a torrent of scholarship and journalism on a once-ignored region, but the reader seeking a basic introduction to the area still has no standard primer with which to start. Central America has yet to produce its classic.

These two new efforts illustrate, in different ways, why writing such a primer is a difficult task. They represent sharply different approaches to the problem, and different mixtures of success and failure. Phillip Berryman’s “Inside Central America” is systematic, direct and frankly polemical, a concise exposition of the argument that the United States has put itself on the wrong side in Central America’s wars. By contrast, Lester Langley’s “Central America: The Real Stakes” is leisurely, chatty and impressionistic, a travel book as much as a political primer. It meanders around the issues and misses one or two entirely. But in the end, it is the better book, for it radiates a richer sense of the flavor of Central American political life.

“None of the Central American states is really a nation,” Langley writes. “Nor do their governments project the rule of law rather than the authority of men. So the ageless tradition of loyalty to family over loyalty to nation or constitution has survived into modern times.”

His portrait of societies dominated by a landed oligarchy allied with aspiring military and commercial classes is not new, but it is nicely drawn. “The harsh reality of Central American society is its militarism,” Langley says. “Central America’s military cadres do not believe their role is to serve the state; they believe they are the state.”

He offers a series of breezy sketches of each country: El Salvador as a battleground where “politics is not the art of the possible, (but) more analogous to a bullfight,” Guatemala as a land of separate Indian and Latino societies in “a war of antagonistic cultures (that) Gen. Custer would have understood,” Nicaragua as “the battered child” of the region--where “As battered children often do at maturity, the Nicaraguans may very well become the batterers.”

The implication for American policy, of course, is that any dream of turning the tiny, semi-feudal countries of the isthmus into “democracies” comparable to ours is doomed. “There is no American solution to Central America’s problems,” Langley warns.

But that sentiment--a theme he states in italics and returns to repeatedly--is almost a truism by now. Even the Reagan Administration’s chief spokesman on the area, assistant Secretary of State Langhorne A. Motley, says with characteristic hyperbole that the aim of U.S. aid is not to turn El Salvador into “a Xerox copy of Greenwich, Conn.”

Langley’s account is colorful and sometimes delightfully readable, but it is lamentably short of rigorous analysis of the issues that Congress and the public must decide. On Nicaragua, the focus of U.S. attention in Central America for more than a year now, Langley’s book is sketchy; he seems to have spent too little time in Managua to come to grips with the dilemmas of the Sandinista revolution. Are the Sandinistas irrevocably pro-Soviet? Are their troubles chiefly of their own making, or merely understandable responses to U.S. pressure? Are the anti-Sandinista rebels known as contras a legitimate political opposition, or merely a creation of the CIA? Should the United States seek the Sandinistas’ overthrow? Langley asks few of these questions and suggests clear answers to none.

Phillip Berryman’s would-be primer, “Inside Central America,” suffers from none of those problems. A knowledgeable and effective leftist critic of U.S. policy, Berryman asks most of the right questions; unfortunately, his answers are too simple and too sure. Berryman’s book may be useful to readers who have already made up their minds and want ammunition in debate, but those who want to grope toward conclusions of their own may find his certainty wearing.

His thesis is avowedly radical. “Since 1979, U.S. policy in Central America has been based on an assumption that revolutionary movements led by Marxists must represent a serious threat to U.S. interests and security,” he writes. “On this point, the difference between liberals and conservatives is merely one of emphasis or accent.” Instead, for Berryman, such revolutions are the only way to improve the lot of the majority of Central Americans, “to reorganize a society--and especially its economy--so that it serves the needs of the poor majority rather than those of a tiny privileged elite.”

That is, indeed, the declared aim of the Sandinistas and other leftist revolutionaries in Central America. But it is also the declared aim of some U.S. liberals and Central American Christian Democrats, who argue that the same goal can be reached without bloody insurgencies. They may be right or wrong, but Berryman merely dismisses them as secret allies of the oligarchies. “While most liberals concede that revolutions do occur--because of the shortsightedness and intransigence of elite groups--their response tends to be too little and too late, a vain hope that political tinkering, like “free elections,” can prop up a tottering edifice,” he writes. Most liberals would respond that their aim is not to prop up the edifice at all, and that their policies, like Christianity, have never failed because they have never been tried.

Berryman frankly calls the idea that the Sandinistas might move toward a Costa Rican-style parliamentary democracy “illusory,” but argues that their authoritarian-populist regime is more authentically democratic. The Sandinistas’ denial of civil liberties and their distaste for pluralism are less important, he argues, than the facts that their motives are good and that they still seem to enjoy the support of a popular majority.

“The Sandinista government enjoys a basic legitimacy from its own people and from the international community,” he argues. “Whether poor Nicaraguans should welcome the contras as ‘freedom fighters’ or not is irrelevant to U.S. foreign policy; the fact is that they do not.”

Those are, indeed, some of the central questions behind U.S. policy toward Nicaragua--only the answers may not be as self-evident as Berryman suggests. Today, the Sandinistas appear to be losing a good deal of their support in the “international community” and perhaps some of the allegiance they once enjoyed among their own people as well. Berryman’s book is an effective statement of one view of the conflict, but only one of many; and his arid style conveys little of the flavor of the life of the people of Central America--regrettably, since Berryman spent more than a decade there.

Readers who want to plunge a bit deeper into the issues of Central America have a growing list of other books to try. Among the best are Walter LaFeber’s “ Inevitable Revolutions, “ a critical history of the United States’ relationship with the area, and Robert S. Leiken’s “ Central America: Anatomy of Conflict, “ a 1984 collection of articles on the choices facing U.S. policy-makers. But those who want the perfect primer--the book that every student will take as a starting point--will have to wait. Central America’s classic is yet to come.