The party faithful who gathered in Tel Aviv on April 14 for a pre-Passover toast heard Benjamin Netanyahu announce that he would amplify Israel's security-and-peace principles at a joint session of the U.S. Congress next month. Surveying the crowd from the podium, the prime minister no doubt took comfort from a recent survey showing that 76 percent of Likud members opposed annexing all of Judea and Samaria. Yet he would also have known that 10,000 party recruits had been newly signed up by uncompromising settler leaders. How, then, to keep the Likud ("Union") together, and in the center of Israel's political mainstream?

In bridging the gap between ideological purism and political realism, the needs of security and the quest for peace, Netanyahu follows in the footsteps of the party's founder Menachem Begin. This much and more become clear in a new collection of essays on the evolution of Israel's Right, From the Altalena to the Present Day (Hebrew), edited by the political scientist Abraham Diskin.

Begin formed the Herut ("Freedom") party—the antecedent of Likud—on May 14, 1948, the day the state was declared. This in itself marked a victory of pragmatism over zeal. Historically, as Herzl Makov, chairman of the Menachem Begin Heritage Center, points out in the book's preface, competing underground factions—like, for instance, Begin's pre-state Irgun and David Ben-Gurion's Haganah—have gone on fighting each other long after the struggle for liberation is won. Yet even after the Haganah fired upon and sank the Irgun arms ship Altalena off Tel Aviv on June 6, 1948, Begin was determined that among Zionists, at least, there would be no civil war. From that day forward, he committed his movement to occupy the center-right position within Israel's parliamentary democracy.

From the first, the deck was stacked against him. Ben-Gurion's Mapai faction, a major element in the labor movement that dominated both the quasi-governmental Jewish Agency and the Histadrut workers federation, captured a 46-seat plurality in the first Knesset elections in January 1949; Herut won a total of 14 mandates. This radical imbalance remained essentially unchanged until 1977.

As for Ben-Gurion himself, not only did he rule out any political reconciliation between the Begin-led camp and his own Laborites; he pledged to ostracize Herut forever by keeping it out of any Labor-led coalition government. So deep did his personal animosity run that in Knesset debates he would refer to Begin only as "the man sitting next to Dr. Yohanan Bader."

Paradoxically, this campaign to blacklist him only further spurred Begin's resolve to keep Herut in the political mainstream. In doing so, he had to overcome the opposition of the Revisionist party, which claimed to be the true standard-bearer of the Zionist Right and the most faithful to the ideology of the Right's founding father and presiding genius, Ze'ev Jabotinsky (1880-1940). Ultimately, though, the Revisionists, like the even smaller Freedom Fighters for Israel (Lehi), would be absorbed into Herut.

The quarantine into which Ben-Gurion had placed Begin started to disintegrate as early as 1954 as a result of the political fallout from a botched Israeli intelligence operation in Egypt known as the Lavon Affair. A decade later, with the Laborites bickering among themselves and Ben-Gurion himself out of power, Prime Minister Levi Eshkol permitted Jabotinsky's remains to be brought to Israel and interred on Mount Herzl, not far from the gravesite of Herzl himself.

In 1965, Begin orchestrated an alignment with the centrist Liberal party to form Gahal ("Herut-Liberal Bloc"), which garnered 26 mandates in that year's elections. It was the entry of Gahal into the Labor-led national-unity government just before the outbreak of the 1967 Six-Day war that permanently broke Begin free from his political isolation. As a cabinet minister without portfolio, he rejoiced over the IDF's liberation of Judea and Samaria.

In due course, however, Begin quit the government, now headed by Golda Meir, to protest its initial acceptance of a 1969 American plan that would have brought the Soviet Union into peace negotiations on the side of the Arabs. Four years later, after the devastating 1973 Yom Kippur war, with Labor's authority increasingly called into question, Begin joined forces with Ariel Sharon to mastermind the birth of the Likud out of Gahal and several smaller factions. His political savvy was vindicated in 1977 with the Likud's smashing electoral victory, overturning Labor's decades-long monopoly on power.

To accomplish this feat, Begin had pulled together settlers, security hawks, predominantly Ashkenazi proponents of a free-market economy, and working-class Sephardim tethered to the welfare state. He reinforced this amalgamation in 1981 by solidifying Orthodox backing for a second term.

The glue that held it all together was the electorate's overriding distrust of Arab intentions. But that did not translate into a corresponding rigidity on Begin's part. The prime minister, writes his former cabinet secretary Arye Naor in From the Altalena to the Present Day, was determined to stay in step with Israel's (shifting) political center, even if that required jettisoning down-the-line ideological purism. His maneuvering did not come without costs. In 1979, his former comrade-in-arms Shmuel Katz left the government over Begin's willingness to trade Sinai land in return for peace with Egypt; Geulah Cohen, another old colleague, broke away to help form the Tehiya party.

A seeming anomaly in this pattern was Begin's 1981 decision to have the Knesset suddenly annex the Golan Heights. But this may have been less the result of hard-line principle than of pique at the Reagan administration, then in the process of selling advanced military weapons to Saudi Arabia while threatening to embargo military aid to Israel over its destruction of the Iraqi nuclear reactor.

Begin resigned the premiership in the aftermath of the botched 1982 campaign in Lebanon, but the story of his years in power is the story of all subsequent Likud prime ministers. Under Yitzhak Shamir, Likud demonstrated far greater ideological steadfastness than under Begin, but even Shamir could not avoid being dragged by U.S. pressure to the 1991 Madrid talks, aimed at achieving a permanent resolution of the Palestinian issue. In the mid-90s, in his own first administration, Netanyahu not only failed to renounce Israel's commitments to the fatally flawed 1993 Oslo Accords but carried out a partial pullback from the West Bank city of Hebron. In 2003, in the midst of the second intifada, Ariel Sharon campaigned as a "Leader for Peace" and accepted the U.S.-backed Roadmap that foresaw the eventual establishment of a Palestinian state. In 2005, when the party rank-and-file repeatedly voted against Sharon's plan to disengage from Gaza unilaterally, he defected to form Kadima.

Netanyahu has now been back in power for two years, once again juggling the demands of his right-wing coalition against those of Israel's fickle international allies. If From the Altalena to the Present Day is any guide, he will continue to navigate the Likud toward the political center—where most voters are—by espousing strength through security along with pliability on the diplomatic front. Like his predecessors, he will strive to bridge the gap between purism and the pragmatic needs of the moment.

This moment, our moment, promises to be as difficult and as hazardous as any faced by any prime minister of Israel since the state's inception.