Palestinian terrorism -- in homes, schools, restaurants and buses; on airplanes, streets and beaches -- ravaged Israel for more than half a century. Between 1954 and 2006, forty-five horrific attacks killed at least ten Israelis. They reached their crescendo between 2002-4, during the Second Intifada, when suicide bombers murdered 128 bus passengers in waves of hideous slaughter.

There is a mournful litany of sites: Kiryat Shemona apartment building (27 dead); Ma'alot (21 school children dead); Savoy Hotel, Tel Aviv (11 dead); Park Hotel, Netanya (27 Passover Seder celebrants dead); Dolphinarium disco, Tel Aviv (21 teen-agers dead); Tel Aviv beach (43 dead); Zion Square, Jerusalem (13 dead); Sbarro pizzeria, Jerusalem (15 dead).

The Israeli government, intelligence agencies and military responded with an array of counterterrorist measures. They ranged from targeted killings to the daring Entebbe rescue, from infiltrating terrorist groups to eye-for-an-eye retaliation and military occupation. Yet to date nothing has succeeded like the construction of a security barrier, now approximately 250 miles long, to prevent terrorist infiltration from the West Bank.

"Something there is," wrote the poet Robert Frost memorably, "that doesn't love a wall." But he lived in New England, not Israel. The security barrier -- part concrete wall and part wire fence -- has been a conspicuous success since construction began in 2002, when Israel was inundated with suicide bombers. Straddling and in places penetrating beyond the "Green Line," the 1949 Armistice Line, it has reduced the number of terrorist attacks to a relative trickle.

Predictably, the "wall" has been sharply condemned (for imprisoning Palestinians and stealing their land) by self-proclaimed defenders of "human rights" who are indifferent to Israeli lives. It has also been denounced on the Right as an ominous foreshadowing of a future border forever separating Israel from its biblical homeland in Judea and Samaria (the West Bank).

For Daniel Byman (Georgetown University and the Brookings Institution), the security barrier is "a double-edged sword," providing "a highly effective counterterrorism device" while making life difficult for Palestinians and complicating peace efforts. In A High Price (2011), his careful analysis of the triumphs and failures of Israeli counterterrorism, he reminds us that Israel's "targeted killings work"; especially during the Second Intifada when Israel "destroyed, disrupted, and deterred" numerous terrorist cells, saving countless Israeli lives. He also understands that excessive Israeli prudence in anticipating, or responding to, terrorism can be "deadly" to its own citizens.

But Israel's "aggressive counterterrorism measures," Byman cautions," complicate efforts to negotiate a peace." He perceives a Palestinian Authority led by Mahmoud Abbas "that is dedicated to making peace" -- if only Israel would cooperate. Not only must Israel "arrest and kill those who would kill its citizens, but it must foster the development of partners with the will and strength to negotiate." Yet when Prime Ministers Barak and Olmert displayed their willingness to give away the territorial store ("land for peace"), Palestinians responded with intensified terrorism.

If Israel is to remain both Jewish and democratic, Byman asserts (more than once), it "cannot continue to occupy a large and growing population that is denied basic rights." He echoes Barak (currently Defense Minister), a stanch Labor party opponent of Jewish settlements, who reiterates the familiar mantra: in the land west of the Jordan River Israel can either become "non-Jewish, or non-democratic." But Barak's solution (settlement evacuation), like Byman's, is based on highly questionable demographic projections.

There is no "massive and growing" West Bank Palestinian population, nor are the overwhelming majority of West Bank Palestinians currently under any rule but their own. In the land between the Jordan and Mediterranean (Israel and the West Bank) Jews currently enjoy close to a 2:1 majority. The Israeli Jewish population is 5,800,000; 1,570,000 Israeli citizens (20%) are Arabs. There are 1,600,000 Palestinians in the West Bank. In Area C (as designated by the Oslo Accords), where Jewish settlements are located, there are 300,000 Jews and 64,000 Palestinians. Areas A and B, inhabited by 1.5 million Palestinians (and no Jews), are governed by the Palestinian Authority.

No reliable demographic data indicate that Israel's considerable Jewish majority within pre-1967 borders and Area C is likely to be seriously challenged, no less undermined, in the foreseeable future. To be sure, Palestinian Arabs, like Arabs elsewhere, prefer their land to be Judenrein. Yet Israeli Arabs are unlikely to leave Israel for "Palestine," if it is established next door. They enjoy citizenship rights, social services, and educational opportunities in Israel that exist in few Arab countries. Affirming the point, more Jerusalem Palestinians have indicated their preference for remaining Israeli citizens than become citizens of "Palestine."

A loud chorus of Israelis on the left, comprising political, intellectual, media, literary, and academic elites, are eager to relinquish the West Bank. It is clearly in their political (disguised as humane) interest to do so. Once eliminate settlements and the geographical base of religious Zionism will be forever lost.

Cassandra warnings on the left, framed as a choice between a Jewish or democratic state, are designed to undermine settlement legitimacy. But even with settlements, given current and projected demographic trends, Israel will remain Jewish and democratic. And it will retain a justifiable presence in the biblical homeland of the Jewish people. That, after all, is the meaning and purpose of Zionism.

Jerold S. Auerbach is the author of Brothers at War: Israel and Tragedy of the Altalena (2011), published by Quid Pro Books.