Is to diminish the occupier's military ability.
It is one of the core reasons that iraq folded so quickly. It is why the Argies got blown away by the Brits.

While I have mentioned before that I believe that Israel is hurting itself by enforcing this 34+ year occupation, I think that what is happening right now, asymetrical warfare, is not going to degrade the Israelis as much as it is the Palestinians. They are the ones oppressing at home more than the Israelis, at this time. The Pals are the ones with rampant institutionalized corruption.
The justice of the Palestinian cause is being crushed under the weight of its worst enemy: its leadership.
As for Nablus, if a bomb factory can fit in a kitchen, then the kitchen that has a bomb factory is a legitiamte target.
Ed

Ed