TO OPEN THIS SLIM volume is to hear a faint cry from a fareway forest, the cry of the last surviving Ache Indians of Paraguay. Of a people estimated to number ten thousand at the beginning of the 20th century less than a thousand Ache may be left today. Fifty per cent of the Ache living in Paraguay in 1968 have since disappeared. They are the victims, this book charges, of a policy of genocide by the government of that isolated South American country.

The definition of genocide accepted by the United Nations includes killing or causing serious bodily or mental harm to members of a national, ethnic, racial or religious group with intent to destory that group. Paraguayan government policy, this book says, permits the Ache to be hunted down and killed, the survivors enslaved, and their culture systematically destroyed because they are in the way of economic expansion.

The Ache's fate is not unique. For more than 400 years after the arrival of the whites, small tribes of Indians managed to preserve their nomadic life as hunters and gatherers of food deep in the forests and jungles of South America. Today, that way of life is under assault in several countries as exploitation of land and raw materials pushes ever deeper into the heart ofthe continent. What is unique about the Ache is that a handful of people from several countries, anthropologists, journalists, philosophers and lawyers, has been drawn to their plight. Richard Arens, a law professor who has represented the Ache before the United Nations, organized their contributions to this volume as he would a case for the jury. Eyewitness accounts are advanced. Prominent experts are called to put the facts into perspective. Philosophers reflect on the moral and legal implications. And Arens concludes with a lawyer's summation urging a commitment to help save the remaining Ache.

But after all the facts and figures, all the moral arguments, the voice which lingers on in the memory, like a faint but piercing flute, is the voice of despair of the Ache themselves. Hunted down and brought to reservations, they sing "weeping songs" about their fate. Nowhere in the book is the charge of genocide made more powerfully than in the mournful poetry of those songs:

We, who were once men, never, never will we rove freely between the trees of the forest . . .

Our daughters, already beautifyl young girls, are now in the houses of the big masters completely tamed from being shouted at so much . . .

This song is for those who will never again be human . . .

The word Ache, the name of the tribe, translates into "the people" or "human being." To the Ache, to be human means to be free, to roam and hunt in the forest. When they are hereded onto reservations and into forced labor gangs, their chiefs totured, their families scattered, they stop being human in their own eyes; they stop being Ache.

The Ache, when they were real Ache, shot many animals in the woods . . .

And now the Ache lie down in ashes, and do not leave their houses any more, when outside they hear the animals' cries . . .

The Ache, oh the Arche are no longer Ache at all . . .

In a sense, the tragedy of the Ache mirrors the tragedy of Paraguay itself. Arens complains about the almost total lack of attention in the American press to the Ache. But the same could be said of Paraguay, now and at almost any time in its history. Paraguay has always been the most isolated of the Latin American nations and a succession of hard dictators generally sought to keep it that way, making, in the words of one of the book's contributors, "a virtue of the country's geography in their war against their captive citizenry."

The current dictator, Alfredo Stroessner, has ruled since 1954. He maintains the repressive system unchanged, but is ending Paraguay's economic isolation by opening the country to large foreign corporations. Major oil companies are searching for petroleum deposits. Lumber companies are cutting into the forests. Two major hydroelectric projects are underway. To make all this possible, roads have been battered through the forests. All these developments encroach on the habitat of the Ache and other Indian groups like them.

Are the Arche simply the latest inevitable victims of the "progress" first set in motion when the whites came to the new world four centuries ago? In a carefully reasoned essay, Monroe C. Beardsley points up the dangers f justifying actions on the basis of a presumed historial inevitability. The crimes committed against the Ache, he argues, "are choices being made today. There is no inevitability about them. And they have no moral justification."

A humane alternative to the continuing destruction of the Ache would be to leave them alone, with enough space to support their society. Variations of this idea have been suggested for a recently discovered Stone Age tribe in the Philippines. In Brazil a national park offered sanctuary to Indian tribes, although the government later undermined that by building roads through it.

A solution could only be attempted in Paraguay with government backing. Given the nature of the government there, that seems unlikely without strong outside pressure. Arens examines the remedies available to the Ache from international organizations and comes away discouraged. He says neither the United Nations nor the Organization of American States offers much hope to the Ache. Only decisive action by the United States, Arens concludes, could effect the policy of the Stroessner regime. The United States has been an important source of both military and economic aid to Stroessner, and Arens argues that "only an explicit declaration by the United States that United States aid will cease if Paraguayan atrocities do not holds any hope for the afflicted." That would require dramatic changes in U.S. policy towards regimes like Stroessner's. Some of President Carter's past statements suggest he would contemplate such changes. Wile he does, the Ache sing their weeping songs.