What is the reason for Israels construction of a wall on their border ?

Israel has been annexing Palestinian land inside the occupied West Bank since 2002 by building a wall that is more than 700 kilometers long.
In June 2002, Israel started construction on its separation wall in the occupied West Bank, citing security concerns. Wide tracts of productive Palestinian land have been taken from them, Palestinian towns and villages have been turned into ghettos, and thousands of Palestinians have been cut off from social services, educational opportunities, and agricultural land as a result of the wall, which has drawn condemnation from around the world. The separation wall, which when finished will be more than twice as long as the 340 km-long Green Line, extends along the Green Line in certain areas, but for the most part, it is inside the West Bank, sometimes by many kilometers.
On July 9, 2004, the International Court of Justice ruled that construction of the wall was “contrary to international law” because it involves the destruction and confiscation of Palestinian property and imposes severe restrictions on Palestinian movement. Further, the Court stated that Israel mustcease forth with the works of construction of the wall being built in the Occupied Palestinian Territories, including in, and around East Jerusalem,” return seized property and compensate Palestinian landowners whose interests have been damaged by its construction.
The Israeli separation barrier divides East Jerusalem and the Palestinian West Bank town of Qalandia. [File: Thomas Coex/AFP].
Further reading: