Untangling the snarls in the ancient troubles of Ireland; The Uncivil Wars: Ireland Today, by Padraig O'Malley. Boston: Houghton Mifflin Company. 481 pp. $20.

For the individual or country that does not learn to come to terms with it, history can be an oppressive and sometimes tragic weight. Outside of the Middle East, perhaps no other part of the world today bears that weight as obviously and as apparently hopelessly as does Ireland.

The Irish, it seems, in both the North and South, are entrenched in history - in a brooding, proud introspection that has periodically erupted in violence, and which over the years has shrouded this island in division and dualism. As in the Middle East, its effect can be hypnotic: Memories of past persecution choke the present and feed future fears.

With ''The Uncivil Wars,'' Dublin-born Padraig O'Malley has accomplished a remarkable task, one that could help break the mesmerism of history. He has provided a dispassionate, reasoned analysis of the dilemma of Northern Ireland - taking into account the broad spectrum of human fears and dreams that have fueled these ''troubles,'' yet without resorting to the emotionalism or oversimplification that all too often cloud discussions of this complicated issue.

The book's intentional detachment may prove forbidding to some readers (and its detailed passages on political structures and elections a bit confusing to others), but Mr. O'Malley's case is both compelling and enlightening. Although he touches briefly on certain historical facts (readers unfamiliar with Ireland's history would do well to consult an encyclopedia beforehand), this study is a contemporary one, centered on interviews with the current key players in the conflict over Northern Ireland.

O'Malley, a senior policy analyst at the University of Massachusetts, Boston, has a long history of involvement in efforts to reconcile the partition of minds and hearts that is far more fundamental to the problem than the geographical partition of the island. In 1975, he helped organize a five-day conference at UMass, Amherst, which brought together a cross section of individuals from Northern Ireland and the Republic for the purpose of discussion and understanding.

In his book, O'Malley does not make a case for hope, per se. In fact, he clearly states that the book is not about solutions. With detached, methodical precision he lays bare the inconsistencies and blindnesses inherent in the views held by virtually every party to the conflict. What he argues for is an agreement by all sides on what is not possible. This in itself would be a major step, since it would require a yielding by everyone involved, an implicit acknowledgment - which does not now exist - of the existence of a valid point of view other than one's own.

This is a fascinating and at times heart-rending study of divisions - divisions not only between groups, but within them. The historic precedent for strife is centuries old, dating from the tribalism that sparked wars among Irish clans and that took on a fractured intensity when the religious-political dimension of Roman Catholic vs. Protestant, Irish vs. English, was added with the arrival of English settlers in Ireland.

O'Malley, however, also examines expertly not only the obvious divisions but also that which is particularly germane to the present conflict - not only the obvious divisions, but all the splintering among ostensibly like-minded groups. It is important to note here, however, that the book is not so much about the average strife-weary citizen as it is about the political leaders who shape the events that perpetuate the strife. Among these leaders there are any number of differences, including, for example, splits within the illegal Provisional Irish Republican Army between individuals pressing for action at the ballot box and those who swear only by the bullet. And there is the plethora of Protestant Unionist groups that pursue varying campaigns for greater integration with Great Britain, for a devolved government, or for outright independence.

O'Malley also offers a keen analysis of the ''outsiders'' - the governments in Westminster and Dublin. And he ultimately argues, quite convincingly, that the South is the key to a framework needed to accommodate some settlement to the problem. Only the South, he insists, can pull the rug out from under the IRA; only the South, he says, can take the steps needed to help assure Protestants of their religious and personal security.

This is in many ways a dismaying book - the hardening of attitudes on every side is all too apparent. But it is also an important and compassionate work. In O'Malley's clear, cool presentation of an almost hysterically emotional situation, there may lie the basis for men and women of both sides finally to find and nurture the common thread of humanity that must be asserted to bind the broken hearts of centuries.