The Israeli defensive wall successfully reduced suicide bombings and may have sparked the Palestinian Civil War.
Passive defenses like walls and fences constrict movement to guarded chokepoints. It allows a small number of troops to patrol and guard a larger range of territory. The Israelis used a multi-layered defense. Informants uncovered Palestinian militant cells. The IDF eliminated many bomb-makers to disable cells. The remaining suicide bombers have to move through guarded checkpoints to reach their targets. This allowed the IDF to intercept attacks and disable entire terrorist networks.
Suicide bombing is cost-effective. This works like an expensive guided missile. It gets an explosive payload inside a crowded building. 151 Palestinian suicide bombers killed 515 Israelis and wounded 3,500 during the Intifada between 2000 and 2005.
The Wall combined with the IDFs counter-network strategy reduced the number of suicide bombers to nearly zero.
Hamas, Fatah, Islamic Jihad lost their most means of attack against Israel. They are attempting to switch tactics and rely on rockets to fire over the wall. The Qassam Rocket is Hamas’s best offensive weapon at the moment.
Most home-made Qassam rockets have a very short range of 2-6 miles and very small payloads of 10-20 pounds, depending on the variation and skill of the producer. It has a short shelf-life as the explosives decompose rapidly. This means Hamas and other militant groups must produce rockets on-demand. Rocket ‘factories’ are also more vulnerable targets than suicide-bomb factories. This is not cheap weapon.
Qassams do very little damage. The warhead explodes outdoors so most of the explosion and shrapnel is absorbed by building walls and concrete.
Qassams only killed 12 Israelis over the past 6 years.
Hamas is trying to make more advanced rockets but this requires greater expertise than they have at the moment. They must build up the requisite knowledge to make WWII-era Katyusha rockets. It’s rather pathetic in a way.
The Wall leads to a de-facto Palestinian State while denying the decentralized militant organizations the means of attacking a common enemy. Without a common enemy, the militants would turn on each other to gain power. The ongoing Civil War between Hamas and Fatah is a probable side-effect of the wall.