MIDWAY through his first year in office, President Jimmy Carter was caught totally by surprise when Menachem Begin, leader of Israel's Herut party, was sworn in as prime minster of the Jewish state. Almost no one in the American government had expected such a turn of events. Begin was vertually unknown. Even Amerian Jewish leaders who were on intimate terms with Israel's Labor Party leadership had tended to ignore him over the years. Now all of a sudden Carter would have to deal with a man whose reputation was that of an extremist and an ideologue.

Carter's advisers quickly tried to find out more about Menachem Begin. He had written two books that told much about his earlier life, but there was no satisfactory biography of the man. Now, as Begin has faded from the scene, such a book has appeared. Eric Silver, a British journalist working for The Guardian and The Observer, lived in Israel from the time of Begin's rise to power through his eclipse. He has produced a workmanlike, often insightful account of this remarkable man.

Menachem Begin is a man who evokes strong feelings in others. During his reelection campaign in 1981, his supporters hailed him as the "King of Israel." But for most of the early years of Israel's existence, Begin was reviled by the Labor Party leadership, especially David Ben-Gurion, and labels of "fascist" and "dictator" were readily attached to his name.

How can one write about a man who seems so riddled with contradiction? On the one hand, Begin could play the part of rabble-rouser, demagogue, planner of underground operations. At the same time, he was a man of courtly demeanor, formal manners, possessing a sense of humor, and capable of the shrewdest political insights. His style was both ideological and legalistic. He would often drive his colleagues to distraction by his endless jousting over words. But just when he seemed most inflexible, he would sometimes suddenly reverse course and justify the change with lengthy hair-splitting analysis.

Silver's solution to the question of how to deal with the complexities of Begin as a personality and politician is to be relentlessly even-handed. As a result, partisans for and against Begin will probably not find great merit in the book. The attempt at objectivity is in many ways admirable, but it comes at a price in Silver's application: he often takes the reader right to the brink of some original insight into Begin's character, but then leaves him to draw his own conclusions. Perhaps this is because Silver sees Begin as "a complex, but not a mysterious man, a paradox but not a puzzle."

But there are puzzling aspects to Begin's career and personality. What accounts for the intensity of his commitment, the single- mindedness of his vision, his narrow self- righteousness, his astute political moves, and finally his unexplained withdrawal from political life in the aftermath of Israel's fateful and flawed war in Lebanon?

For those who want answers to these kinds of questions, Silver provides little more than a historical narrative of the man's life, with only a few efforts at interpretation. Much of the detail will be familiar to anyone who has read other accounts of Begin's career, but Silver adds a few points from interviews with Begin's sister, for example, or from conversations with some of his political cronies. Begin, however, would not agree to be interviewed for the book.

Psychological interpretations of political figures are often misleading or trivial, but in Begin's case one wishes for some genuine psychological insights. The early life of the man is filled with potentially important events. For example, Begin reportedly was greatly influenced by his father. But only a few pages are devoted to these early years.

More attention is paid to Begin's relationship to the man he called his mentor and the greatest influence in his life, Vladimir Ze'ev Jabotinsky. Silver notes, however, that there was little intimacy between the two, and that Jabotinsky was on occasions quite critical of Begin. When Jabotinsky died in 1940, Begin's world collapsed. Pursued by the Soviet secret police, he chose not to escape. He felt so hopeless that prison seemed preferable to continuation of the struggle without the leader.

One is tempted to see Begin's return to politics in 1944, and much of his subsequent struggle, as a personal attempt to measure up to Jabotinsky's ideals. Years ago political scientist Harold Lasswell -- with Freud's insight in mind -- hypothesized that men turn to politics to overcome feelings of damaged self-esteem. The adulation of the crowds makes up for feelings of inadequacy. Silver's account hints at something comparable in Begin's case, but leaves the reader with more questions than answers.

If psychological insight is not the strength of the book, the author makes up for this shortcoming by a steady hand as a political reporter. The story of Begin in opposition, then as prime minister, is well told. Some new details about Begin's role in the massacre of Arab villagers at Deir Yassin in 1948 are brought to light. But in the end, Begin the artful politician remains elusive.

Part of the problem, I believe, is that Begin used rhetoric, legalisms, and highly charged ideological language to mask his finely calculated political moves. This was a man who understood power and how to use it. He knew how to wear down his adversaries with mind-bending legal arguments, but it was not the law that motivated him. He had his eye clearly set on the one overriding goal of his career: the creation of Eretz Israel within all the territory west of the Jordan River.

This was the part of Jabotinsky's vision that Begin most wanted to fulfill. To that end, he was prepared to abandon Israeli claims in Sinai, to sign a document calling for "legitimate rights for the Palestinian people," and to authorize a war against the PLO in Lebanon.

Curiously, Begin's commitment to Eretz Israel did not seem to grow out of a love of the land. It was Moshe Dayan, not Begin, who had a deep feel for the land and its history. Begin rarely visited the territories that he invariably called by their Biblical names of Judea and Samaria. He had none of Dayan's passion for archeology. Nor was his concern with the territories rooted primarily in security, or even in the Bible. But whatever its origins, Begin's commitment was unshakeable. Jimmy Carter and Ronald Reagan both tried to push him toward a formula of "territorial compromise" with Jordan, but Begin would have none of it.

Golda Meir, among others, worried that Begin's intransigence would produce a sharp political reaction from the Americans. In her memoirs, as Silver notes, she said that she could never convince Begin that Israel needed the Americans more than they needed Israel. One could not assume, she wrote, that American Jews would be able to force an American president to act against his better judgment. But Begin, according to Mrs. Meir, was intoxicated by his own rhetoric. He convinced himself that if Israel could go on telling the United States that it would not give in to pressure long enough, one day the pressure would just vanish.

But what Golda Meir saw as a measure of Begin's political naivet,e can be seen, with the advantage of hindsight, as an astute judgment about the workings of the American political system. For Begin, at the peak of his career in 1979-1980, there must have been great satisfaction in knowing that he had, in all likelihood, set the borders of Israel for the indefinite future.

In his later years, Begin's health failed, he lost his wife, who had been his closest friend and companion, and he finally withdrew entirely from political life into self-imposed isolation. He had presided over a rapidly deteriorating economy; he had been misled, perhaps even betrayed, by his generals in the Lebanon war; but his mentor, Ze'ev Jabotinsky, could not have faulted him for the struggle he waged for Eretz Israel.

Eric Silver's book helps us to understand much about the extraordinary political career of Menachem Begin. It serves as a fine introduction, and it is both the merit and the shortcoming of the book that at the end one wants to know more about what motivated this remarkable and flawed personality. Silver convinces us that Begin is a man worth knowing, but leaves us in suspense about who he really is.