Recently, I was among more than 400 American rabbis, cantors and rabbinical and cantorial students who signed an open letter to Israeli Prime Minister Benjamin Netanyahu expressing our deepest concern about his government's latest settlement decisions.

What especially prompted the letter was a decision he and his government took to build a new settlement in an area east of Jerusalem known as E1, which every prime minister since Yitzhak Rabin has promised the United States that Israel would not undertake in advance of a final-status negotiations. If built, this settlement would cut off the north and south of the West Bank and effectively block the establishment of a contiguous Palestinian state. We see the building of E1 as a dagger aimed at the heart of a two-state solution.