Other Benefits The Green Line is crossed by numerous dirt roads and it is impossible to patrol it. Many Palestinians take advantage of these roads to come to work illegally in Israel or to get between parts of the Palestinian administered territories to avoid checkpoints. Some also cross to carry out terror operations and theft. Since 1994, Palestinians, sometimes in cooperation with Israeli middlemen, have stolen thousands of automobiles as well as farm machinery and animals http://www.jewishvirtuallibrary.org/jsource/Peace/fence.html
That graph is attacks in Judea and Samaria only.
Jerusalem has no fence yet, deaths are drasticly down over the same period. I am used to hearing a bomb a week go off in the city before the fence was built, I have not heard a bomb in over a year.
That is my point, terrorism is down, the fence has nothing much to do with it. The attacks into the Arab areas by the IDF and the house to house weapons confiscations began and terrorism dropped of AT THAT POINT, before the fence was even started.
The fence does not keep Arabs out, it keeps the IDF out when it is finalized. That will increase attacks, not decrease them. In 2001 I could hear automatic weapons fire from the surrounding villages into Jerusalem on the borders almost every night. The fence did not stop that either, nor can it once it is built. Chain link fences do not stop bullets flying over.
The fence is highly over rated. It purpose was to draw a line in the sand for Israel to surrender. Jordan and Egypt and Lebanon have a perfectly fine fence.
But they never stopped a war. Building another fence inside Israel to hide behind will not either.