I realize that the purpose for the wall doesn't accord with your ideological position but if you look at the statistics of the number of suicide bombings since the wall was mostly built you will find a strong correlation.

"Members of al-Aqsa Martyrs' Brigades, Hamas, and the Palestinian Islamic Jihad have been less able to conduct attacks in Israel, the numbers of which have decreased in areas where the barrier has been completed"

Some opinions from jihadists:

"Palestinian Islamic Jihad leader Ramadan Abdallah Shalah complained to the Qatari newspaper Al-Sharq that the separation barrier "limits the ability of the resistance to arrive deep within [Israeli territory] to carry out suicide bombing attacks, but the resistance has not surrendered or become helpless, and is looking for other ways to cope with the requirements of every stage" of the intifada."

"Palestinian Islamic Jihad leader Ramadan Salah said that the barrier is an important obstacle, and that "if it weren't there, the situation would be entirely different."