Security is a key issue in Israel-PA Negotiations

From Times of Israel, by Kenneth Levin:

Former Israeli Prime Minister Yitzhak Rabin, like the authors of UN Security Council Resolution 242 - still the foundation stone of Israeli-Arab peace negotiations - recognized that Israel's pre-1967 armistice lines left the nation too vulnerable to future aggression. He insisted Israel must hold onto a significant portion of the West Bank to block traditional invasion routes and to protect both Jerusalem and the low-lying coastal plain, home to some 70% of the nation's population.

     In his last speech in the Knesset before his assassination, Rabin declared: 

"The borders of the State of Israel, during the permanent solution, will be beyond the lines which existed before the Six-Day War. We will not return to the 4 June 1967 lines. And these are the main changes, not all of them, which we envision and want in the permanent solution: A. First and foremost, united Jerusalem, which will include both Ma'ale Adumim and Givat Ze'ev - as the capital of Israel, under Israeli sovereignty, while preserving the rights of the members of the other faiths, Christianity and Islam, to freedom of access and freedom of worship in their holy places, according to the customs of their faiths

B. The security border of the State of Israel will be located in the Jordan Valley, in the broadest meaning of that term.

C. Changes which will include the addition of Gush Etzion, Efrat, Beitar and other communities, most of which are in the area east of what was the "Green Line," prior to the Six-Day War.

D. The establishment of blocs of settlements in Judea and Samaria [the West Bank]."

Nothing has changed in the last 18 years that would diminish Israel's need to retain the areas referred to by Rabin. The topography of the region has not changed, and the nations around Israel have not become more peaceful or more reconciled to Israel's existence. Prime Minister Netanyahu's vision of defensible borders for Israel essentially conforms to the parameters laid out by Rabin.

From Times of Israel, by Avi Issacharoff:
The fate of the Jordan Valley, and the wider issue of security arrangements, are emerging as a major obstacle in the path of the indefatigable Secretary of State John Kerry's peace efforts. Gen. John Allen's painstakingly drafted security proposals have not produced a breakthrough. Both sides are insisting on keeping the Jordan Valley.
    In 2007, the IDF's Planning Directorate drew up Israel's security overview ahead of a peace treaty with the Palestinians that specified the need for an ongoing IDF presence in the Jordan Valley for a lengthy but undefined period. On the basis of that overview, then-Defense Minister Ehud Barak drew up a document, which became known as the "Eight Points," which he discussed with President Bush when he visited in January 2008. Barak stressed to Bush the imperative for IDF troops to remain in the Jordan Valley for the long term - a generation, according to some Israeli sources - to ensure no influx of terrorists or weaponry.
    In taking this position, Barak was merely reiterating the stance that had prevailed since the Yitzhak Rabin era in the early 1990s. And it holds today: 

A senior Israeli official said this week that if there is no Israeli presence in the Jordan Valley, "there will be rivers of blood."