By creating a security wall, Israel is showing that it's wary of peace talks, which have slowly progressed over the years. The wall is actually a detriment to these peace talks, and analysts agree on this point for the most part. Israel should focus upon making strides for peace rather than defending itself against a potentially non-existent enemy.
The Israeli security wall between the West Bank and the rest of Israel proper is almost single handedly responsible for the end of the second intafada and the end of suicide bombings in Israel. The peace process has continued for generations now, with violence not noticeable decreasing, and only moves such as the wall have helped secure the Israeli people.