Each year, thousands of North American Jews make aliya and relocate to Israel, casting their lot with the state. A new book by Sara Yael Hirschhorn examines those American immigrants – more than 60,000 – who settled in the West Bank. In City on a Hilltop: American Jews and the Israeli Settler Movement, Hirschorn tackles the topic in a comprehensive, sophisticated and nuanced manner.Nevertheless, I found much of the contents of this book deeply disturbing, as it became clear that so many American Jews gradually abandoned their liberal backgrounds and replaced them with radical and often extremist ideologies and violent practices toward their Palestinian neighbors.Hirschhorn is on the faculty of the Oxford Center for Hebrew and Jewish Studies at the University of Oxford in England, and mined the depths of archival materials for her book. Her findings are based on periodical press, media, literature, film, music, the Internet, and oral histories, and are presented in a thoughtful and thorough manner. The use of oral histories and interviews makes the book both real and readable, and allows the reader to dig deep into the lives of many of the American Jewish settlers Hirschhorn came to know during her research.Especially interesting were the chapters about Efrat and Tekoa, settlements just south of Jerusalem that were both founded by American Jews. Rabbi Shlomo Riskin of Efrat and Bobby Brown of Tekoa both came from more liberal American backgrounds and put down their roots in the West Bank, when there was little to be found in Gush Etzion except caravans, tents and dust.Over and over in the book, the author depicts the clash between a liberal self-image of many of the settlers and what she calls “settler realities.” However, I am not convinced that many of these settlers were as liberal as Hirschhorn suggests. Many grew up in Orthodox Jewish homes and communities in the US, especially in the New York area, and especially in Brooklyn, which were not really all that progressive.From Hirschhorn’s reporting, it seems that these settlers ignored from the beginning the existence and rights of indigenous Palestinians in the West Bank. Many of the descriptions of their settling “empty hills” reveal that the Palestinians there were largely invisible until the first intifada. One significant exception was Rabbi Menachem Froman of Tekoa, who was well-known for his ideas on religious reconciliation with Palestinians.But most disturbing was the phenomenon of American Jewish settlers who became violent and extremist after moving to the West Bank. Hirschhorn describes in great detail the Hebron massacre carried out by US-born physician Baruch Goldstein, as well as other prominent cases of political violence, including Era Rapaport and the Jewish underground, and the Kahanist network and other Jewish terrorists. While these actions were clearly denounced by mainstream Israeli Jews, things were murkier among the settlement population. The late prime minister Yitzhak Rabin repudiated Goldstein’s actions in an important speech to the Knesset: “This murderer... grew in a swamp whose murderous sources are found here and across the sea; they are foreign to Judaism, they are not ours. To him and to those like him we say: You are not part of the community of Israel... Sensible Judaism spits you out... You are a shame on Zionism and an embarrassment to Judaism.”As Hirschhorn clearly demonstrates, the acts of many on the lunatic fringe of the settler movement turned public opinion against settlers in general and American settlers in particular. After the Goldstein massacre in Hebron, the American-Israeli settler was presented as a pariah in the media in Israel and internationally.This excellent book offers a fascinating though troubling look at American Jewish settlers who have come to live across the Green Line since 1967. It raises serious questions about how people with liberal values could engage in such an illiberal project and analyzes the complexities of the movement. Ron Kronish is a blogger and writer. His new book The Other Peace Process: Interreligious Dialogue, A View from Jerusalem, will be published in August by Hamilton Books, an imprint of Rowman and Littlefield.