Fifteen percent of the total Jewish settler population in the West Bank are Americans, a Oxford University scholar revealed Friday, detailing for the first time the number of US citizens living beyond the Green Line, according to Newsweek. Speaking at the Limmud conference in Jerusalem, Sara Yael Hirschhorn, in a promotional lecture for her soon-to-be published book, said that out of the approximately 400,000 Jews living in the West Bank, 60,000 were Americans. The figures did not include east Jerusalem, Newsweek added."This provides hard evidence that this constituency is strikingly over-represented, both within the settler population itself and within the total population of Jewish American immigrants in Israel," Hirschhorn said. Anat Ben Nun, director of development and external relations for the dovish Israeli NGO Peace Now, said that the findings reveal that the settlement enterprise has expanded beyond its internal dimensions and has morphed into "an international problem.""Unfortunately, while the Obama administration has been persistently vocal against settlement developments, some 60,000 American citizens are taking an active part in an attempt to make the two state solution impossible," Ben Nun said. "With no possibility for real bilateral negotiations in sight, the American administration must be actively involved in promoting a solution to the Israeli Palestinian conflict through the international arena," she added. Hirschorn, whose efforts span over a 10-year period, went on to say that despite common tropes labeling American emigrants to Israel as Right-wing or religious ideologues , many of the settlers were left-leaning, educated professionals with strongly held Zionist beliefs."What my studies reveal is that they were young, single, highly-educated... upwardly mobile," she said. "Most importantly, they were politically active in the leftist socialist movements in the US in the 1960s and 70s and voted for the Democratic Party prior to their immigration to Israel."Hirschorn went on to say that the picture that emerged from her years-long study of American settlers "is one of young, idealistic, intelligent and seasoned liberal Americans who were Zionist activists, and who were eager to apply their values and experiences to the Israeli settler movement," according to Newsweek.The US State Department's official position is that under international law, Israeli settlements are illegal.