RICHARD E. FEINBERG's The Intemperate Zone 2 is the best antidote in years to the know-nothing spirit now rampant in the higher reaches of the government. The author's aim is to define and defend the legitimate U.S. interests that touch the Third World. His "neo- realism," as he calls it, shares the traditional goals of U.S. foreign policy. He is for an "open and growing international economy." The nation needs "a strong military" to "check the expansionist tendencies of the one nation that could physically threaten us--the Soviet Union." But he forcefully challenges many prevailing notions about the nature of U.S. interests in the Third World and the connection between the U.S.-Soviet competition and the process of political and economic development that has been going on in Asia, Africa and Latin America since the Second World War.

The author was a member of the Policy Planning Council in the Carter administration but sprinkles his criticism impartially. Indeed the most incisive passages deal with the mistakes of the last Democratic administration in Iran and Nicaragua. What is so refreshing about this book is an awareness throughout that history is indeed being made in the underdeveloped nations and that without trying to understand it the United States is fated to find itself at war with billions of people who do not need to be our enemies. The know-nothing approach to the Third World relies on metaphors, hysterical language, and the imagery of the chessboard. As U.S. Marines now head toward Central America, the American national interest is explained in terms of dominoes, the Brezhnev Doctrine, and the protection of vital resources in our "backyard." Feinberg prefers to examine the concrete conditions in the nations we propose to remake before we commit ourselves to hopeless aid programs or protracted guerrilla wars. Most sensibly, he asks policymakers to take a hard look at the assumptions on which the enormous mobilization of American resources rests.

Any sensible political strategy, particularly for operating in other people's countries, must start with an assessment of the political forces at hand. In country after country, the author notes, "we have routinely counted on business or the military to guarantee our interests" without understanding what weak reeds they are. Feinberg skillfully shows how changes in the world economy, the competition among banks to increase the indebtedness of Third World countries, the survival strategies of the multinational corporations, and the rapid integration of a "one-world economy" are creating fundamentally new conditions in which the interests of local businessmen no longer necessarily coincide with either those of the U.S. government or of U.S. corporations.

His assessment of the local military as an instrument of U.S. strategic interests is shrewd, and timely. Peasant conscripts fighting to preserve the privileges of their own oppressors do not offer an effective defense of American interests. As we see in El Salvador today, there is a fundamental conflict between what we not so long ago called the "battle for hearts and minds," the effort of a government challenged by a broad-based insurgency to establish its legitimacy, and the struggle of a beleaguered military junta to establish physical security and control, which inevitably involves killing civilians in large numbers. In a civil war passion runs high, and Central American generals believe, contrary to much evidence, that large doses of official terrorism will eventually win the respect, if not the affection, of the populace. U.S. counter-insurgency experts know better and counsel moderation. But the local generals know that once the United States is committed to not "losing" a country it never had it will continue to finance their crimes while deploring them from time to time. This classic situation, once again reaching crisis proportions in Central America, is tailor-made to expose U.S. impotence and confusion. Feinberg shows how the loss of American power over the last generation has been accelerated by the weakness of our leaders for military ''solutions" that create, strengthen, and legitimize enemies of the United States.

Feinberg understands no less than the administration that the world is a dangerous place. But he counsels us not to confuse analysis and propaganda and to be sure we can distinguish real threats from fictitious or exaggerated ones. Getting military appropriations for El Salvador or money to finish off the junta in Managua may be politically easier if you say that the outside agitators from Russia, Cuba, or Nicaragua are the backbone of the insurgency, but it is a dangerous myth because the facts are otherwise. Even if the flow of arms from Russia and its friends were far greater than it has been proved to be, the basic political situation in El Salvador would remain, and so, given U.S. self- definition of its national interests, the American dilemma.

The author urges greater clarity about goals in order to resolve such dilemmas. Keeping Soviet bases out of the Western Hemisphere is an important and eminently achievable goal. Feinberg traces the mixed record of the Soviets around the world. Though more formidable a military power than ever, the Soviets, having been thrown out of Egypt, Somalia, China, and elsewhere, are more isolated politically than at any time since the end of the war. Their system is admired nowhere and their economic problems are serious. They show no interest in taking on the United States in its self-described "backyard," but U.S. policymakers seem determined to give them credit for revolutions they did not instigate and do not control, thereby creating the very situations in which Soviet influence in the region will increase. (Feinberg effectively shows how local communist parties function as clumsy instruments of Soviet penetration.)

But containing a possible Soviet military challenge is quite different from the King Canute policy of preventing indigenous revolution on the grounds that it might become pro-Soviet. Feinberg points out some of the more obvious but frequently forgotten political facts of life of our hemisphere. For countries once occupied by U.S. Marines anti-U.S. rhetoric is part of the political landscape but no leader can afford to base his policy on it if the United States is willing to accept coexistence. He exposes the myth that radical regimes will withold vital resources from the United States. The poorer the country, the more committed to rapid development, the moreit must seek to sell its goods, including natural resources. Multinational corporations are sufficiently adaptable to understand this. But, unfortunately, the U.S. government is not.

Enormous dangers for the American people now lurk in the unresolved problems of the world economy. Some of the best pages in this path-breaking book deal with these. But while dangerous romantics in power are setting the stage for a generation of war in Central America, the important security questions, the ones that may even have solutions, are shoved aside.