JERUSALEM — When Peace Now released a report recently charging that 40 percent of Jewish settlement territory in the West Bank is built on privately owned Palestinian land, the report’s co-author said she hoped it would serve as a wake-up call to principled Israelis.

Hagit Ofran, the granddaughter of famed Israeli philosopher Yeshayahu Leibowitz and the product of a religiously observant family, said she wanted the findings — aimed as much at the settlers themselves as at the outside world — to present an acute moral dilemma to the decent people who live on what she argues is essentially stolen property.

In a few cases, she said, that has happened.

“People feel very uncomfortable about this report,” said Ofran, who co-authored it with Peace Now’s longtime settlement watch team director, Dror Etkes. “Settlers approached me and asked me about my sources because they don’t want to be land stealers. I’m sure there are people who don’t want to live illegally or on stolen land.”

For the most part, settlers reacted to the report dismissively, critically or angrily.

“There is nothing new in Peace Now’s claims,” Emily Amrousi, a spokeswoman for the Yesha Council, the main settlers’ group in the West Bank, told reporters. “As usual in the struggle against the Jewish settlements, all means are valid. The State of Israel has not built communities on private lands since 1979.”

Settlement advocates said the data on land ownership are based largely on specious claims — unsubstantiated, unofficial and, in some cases, unclaimed property deeds. Some said it also ignores a pattern of Arabs building on Jewish-owned lands.

Government spokesmen said they would have to review the data before commenting on the report’s accuracy.

But Peace Now said the report, called “Breaking the Law in the West Bank,” is based on Israel’s own records.

The formula used to determine the findings was relatively simple: Peace Now overlaid maps of private Arab property in the West Bank, obtained illicitly from Israel’s Office of Civil Administration, with maps of the settlements themselves.

The results showed that of the land the settlements occupy, approximately 39 percent is under private Palestinian ownership. Of the remainder, 54 percent is state owned, 1.3 percent is privately owned by Jews and about 6 percent is “survey land” with unclear ownership.

The report did not consider the reliability of the Civil Administration maps, which critics have since questioned. But the use of Israeli maps means that, if anything, the extent of Palestinian land ownership is estimated conservatively, Ofran said.

Facing anger and bewilderment from both pro- and anti-settlement activists, Ofran said the findings were both painful and surprising.

“Making this discovery did not bring me joy,” Ofran told JTA in an interview Tuesday at Peace Now offices in Jerusalem. “I always believed that at least according to Israeli law the settlements were on state land, even if the world held that the land was illegally seized.

“It’s very sad to me that very idealistic people, good people, people who would be upset if their own child stole a pencil, are living on stolen land,” she said.

“I’ve met people who say, ‘OK, this may be true, but why are you doing this? Why be a stinker? You are giving Israel a bad name.’ I have no interest in giving Israel a bad name; I’m interested in Israel not being bad.”

As the product of a family steeped in religious Zionism, Ofran said she feels a strong emotional connection to the settlers, whom she regards with a combination of admiration and disappointment. Ofran admires them for their idealism, motivation and Zionism, but is distressed that their energies are being directed toward an enterprise that seems doomed to ruin.

“In the end, the solution to this conflict will be two states: a Palestinian state beside Israel and the uprooting of the settlements,” she said. “Everyone knows this.”

Imagine, Ofran said, if the settlers’ energies instead were directed toward building Israel proper.

“If they turned these energies to things connected to building our society rather than building war with our neighbors, they would have a much more constructive impact on Israel,” Ofran said. “But they’ve isolated themselves. They’ve disengaged.”

Ofran said her grandfather, who died in 1994, had a big influence on her life and her political ideology. A prolific writer, philosopher and Torah scholar, Leibowitz’s critiques of Israeli policy toward the Arabs made him a reviled figure among some Jews and an intellectual hero to others.

Though Ofran, 31, said she decided as an adult to stop being religiously observant, she is still steeped in the world of Talmudic exegesis. She has continued to study Talmud at institutions such as Jerusalem’s Hartman Center, and she appended a Talmudic adage to last week’s Peace Now report called “One Violation Leads to Another.”

“When you begin breaking the law, you justify worse and worse things,” Ofran said.

People who chastise their children for committing the sin of stealing are themselves countenancing stealing land, attacking Palestinians, even pilfering olives from Palestinian groves, she said.

“This, to me, epitomizes how these people have been corrupted,” Ofran said. “The Land of Israel blinds them. You can’t steal a pencil, but when it comes to the olives of Palestinians, it’s OK. It hurts me to see this.” Still relatively new to the job, Ofran is sufficiently anonymous to settlers that she can visit settlements in the West Bank to survey their growth without too much trouble. She talks to residents when she can, keeping her identity discreet.

At some settlement outposts, residents have learned to recognize Peace Now’s vehicle and they don’t allow Ofran in the gate. In such cases Ofran tries to photograph the settlement from nearby hilltops, but she said the results aren’t as good.

Ofran’s partner, Etkes, who has been tracking settlement growth for several years, has been assaulted or run out of settlements on several occasions. Ofran and Etkes supplement their site visits with aerial photography and mapping technology to track the settlements’ growth.

“Part of why I took this job was because I love to hang out in the territories,” Ofran said. “The Land of Israel is an important thing, and I love it.

“I especially love Hebron. But we cannot be there as occupiers. For 500 Jewish settlers to live in Hebron, thousands of Palestinians must live under effective house arrest. ‘This is a mitzvah borne of a sin,’ ” she said, again quoting the Talmud.

For the time being, Ofran said, Peace Now is focusing its legal strategy toward uprooting illegal West Bank outposts. Though these outposts are officially illegal, no action is taken to uproot them unless a court orders the authorities to act. Peace Now petitions the courts to take that action.

Ofran said the work is her responsibility as a Zionist.

“The goal is political — to force the Israeli public to reckon with the price of the settlements,” she said. “It’s a terribly foolish thing we do. We invest a fortune in money, people, construction, fences, roads and soldiers, while we know that in the end we’ll have to leave it all. And we do this at the expense of investing in our country, in our educational system, in our society.

“I still believe in the democratic Jewish state, and I’m very afraid we’ll get into a situation where we cannot realize this dream,” Ofran said, citing figures that show 260,000 Jews in the West Bank living among as many as 3 million Palestinians. “I still believe we can save the Jewish state — by pulling out of the territories. This is the only way.”