A Marriage Shot Down Over Israel : BLACK BOX <i> by Amos Oz; translated from the Hebrew by Nicholas De Lange in collaboration with the author (A Helen and Kurt Wolff Book</i> /<i> Harcourt Brace Jovanovich: $21.95; 243 pp.) </i>

“There is a land but we have not found it. Some jester in disguise has crept in and seduced us into loathing what we have found. Destroying what was precious and will not return.”

Ilana is speaking at the end of the “Black Box” by the Israeli novelist Amos Oz. She is the apex of the matrimonial love-hate triangle that provides the novel’s ostensible subject. But her words, and the triangle itself, stand for a larger theme: the unresolved question that troubles and divides thoughtful Israelis over their nation’s character and destiny.

Oz uses letters and telegrams among Ilana, her former husband, Alec, and her present husband, Michel, to tell a bitter, comic and ultimately mournful story of three talented and inflamed people whose lives and passions simultaneously sustain and strangle each other. The letters are tinder; they quarrel, goad, cajole, entreat and lament; they are a series of alarms, some of them false, that refuse to be shut down.

Years after a violent and messy divorce, Ilana writes desperately to Alec, now living in the United States as a professor and author of books on the subject of fanaticism. Their son, Boaz, in his late teens, has become unmanageable and has just been expelled from his school. Ilana’s letter is a cry for help; it is also the first shot in a renewed battle, half warfare, half seduction, with her former husband.

Alec, who has inherited money, sends some, along with a brutally withering letter. He also uses his high-level political connections to rescind Boaz’s expulsion. Meanwhile, Michel, a North African immigrant, a teacher of French, and the leader of an extremist religious splinter group, uses his own low-level, on-the-ground connections to locate Boaz and get him a job.

It is the first pass in a joust between the two men that continues through the book. One of the prizes is Boaz, whose stormy struggle to grow up takes him in and out of jobs and run-ins with the police until, at the end, he has become the oddly assured leader of a tiny hippie commune engaged in reviving an abandoned house and property in the countryside.

Another prize is Ilana. The bitter anger between her and Alec conceals an obsessive passion that draws them together even as they tear each other apart. Her love for Michel, more settled and maternal, remains, however; and he fights Alec for her to what will become a draw that is unresolvable except, perhaps, by death.

It has to be a draw. Because Ilana, apart from being a vivid, passionate, suffering and sometimes insufferable woman, is also the soul of Israel. Boaz, renouncing the concerns and hatreds of his elders, stands for a frail and insubstantial hope for Israel’s future. Alec and Michel, warring rivals and linked at a profound level neither can fathom, are struggling with each other over the soul and future of their country.

Each man represents one side of Israel’s internecine moral and political struggle. Alec is a scholar-warrior, a member of the Labor Party elite that dominated the country for its first quarter-century, and that seemed to have mastered the impossible task of combining a humane tolerance and intelligence with a formidable ability to maneuver tank battalions.

Michel, a Sephardic immigrant, is part of the underclass. Often patronized or ignored by the elite, it worked hard, prospered and gradually gained strength until, supporting Menachem Begin and the Likud, it broke labor’s ascendancy and began a gradual overturn of class and politics. They stood for a big, as against a little, Israel; the settlement as well as the occupation of the West Bank, and a greater intransigence, with strong religious elements, against Arab claims.

“The Black Box”--the title, referring to the instrument that analyzes plane crashes, is an image for Alec’s and Ilana’s dissection of their former marriage--can become prosy at times. Occasionally, the epistolary form has to carry too much narrative and descriptive weight.

But it is astonishingly successful in fusing the histories and characters of Alec and Michel with what they represent. They are utterly visible and believable as individuals, though pitched in a perpetual emotional overdrive. Yet, in the way each one drinks coffee or takes a walk, we get an entire chapter of national history.

Oz, whose background and sympathies link him with his country’s liberal tradition, seems to be harder on Alec. But ultimately, he is unsparing and loving--perhaps the word is “heartbroken”--with both.

Alec’s detachment and chilly arrogance is, in a way, the author’s argument that those who ran the country for so long, who were so admired abroad for their civility and prowess, had become estranged from the reality of a small Middle Eastern country. (Alec can be violent--he beat up Ilana when they were married; likewise, the 1967 war wasn’t won with words of reason.) The weapons he uses in his struggle with Michel are his checkbook--he keeps sending him money--and his connections with generals and Cabinet ministers.

Michel, on the other hand, knows sergeants, police chiefs and the heads of government bureaus that award building permits. His portrait is the most extraordinary thing in the book.

He is a warm, loving man. He has pillow fights with Ilana and their daughter, Yifat. He cooks them hamburgers and fried potatoes. He involves himself intimately with Boaz, using a kind of tough love. (Alec writes checks). He is intensely religious; his religion is inseparable from the clandestine efforts of his group to organize settlement in the West Bank.

None of this changes throughout the book; yet everything does. At the start, Michel is poor. Using Alec’s money along with contributions mysteriously raised abroad, using the help of sympathetic middle-level officials--their level rises as the book proceeds--he gets rich.

It is Calvinist riches. Michel’s holy biblical mission is to take possession of the West Bank. He and his people are buying up property there and, in the nature of things, they stand to make a killing. The killing, as Alec bitterly perceives, may someday become literal. Expansionism may destroy Israel. “You will boil in oil and mutter thrice ‘Holy.’ ” For Michel--infinitely aggressive, kind and naive--real estate is holy war.

All this suggests only a part of Oz’s accomplishments. Ilana’s anguish as she struggles against Alec’s and Michel’s struggle, a fiery and comical correspondence between Alec and his lawyer, the elusive serenity of Boaz--is he signaling some ideal third kind of resolution for Israel?--these are some of the elements that enrich the book.

And there is a vein of poetry that runs through; a love of place, of the countryside, of Jerusalem at night. The rage and agony, after all, arise from the passion of the characters, for what each thinks of as his or her differently promised land.