When Faris Abu Hasan was deciding where to send his two young daughters to school, one factor stood out above all others: test scores.

So Abu Hasan opted against the beleaguered local government school, and chose instead the Islamic Basic School for Girls, where the classes were small and the teachers offered individual attention in math, science, history and English.

"I wanted them to go to the best school in Nablus. And this is the best school in Nablus," said Abu Hasan, a lawyer.

But the school is associated with Hamas, the Islamist movement that Israel considers a terrorist organization. One night last week, the Israeli military raided the school -- confiscating computers, trashing desks and ripping student artwork from the walls. The school was ordered shut for three years.

The operation was part of a much broader crackdown that Israel has recently initiated in the occupied West Bank against Hamas's extensive social services network. While Hamas is probably best known for its military wing -- which champions attacks against the Jewish state -- it is the group's sponsorship of schools, medical centers, orphanages and food banks that gives it much of its power and helped it sweep Palestinian elections in 2006.

With a fragile truce holding in Gaza, Israel has turned its attention to undercutting Hamas's charity work in the West Bank. The effort is needed there, Israel contends, to keep the group from seizing power from the more pragmatic Fatah-led Palestinian Authority, much as it did in Gaza last year.

But the raids have also sown resentment and have put the Palestinian Authority in an awkward spot: Although Hamas is seen by Fatah leaders as a mortal threat, it also provides valuable services that the Palestinian Authority can't easily replicate. Every time Israel cracks down and closes a school or a medical center, it leaves a void that makes people more dissatisfied with the Authority.

"The one served best by these crackdowns is Hamas itself," said Jamal al-Muhaisen, governor of Nablus and a Fatah member. "It's embarrassing for the Palestinian Authority that we cannot protect these institutions that are under our control. It causes the people to feel sympathy for Hamas."

The damage is especially severe in Nablus, Muhaisen said, because the city of 135,000 is supposed to be a model of Palestinian autonomy. Israel passed control of security in the city to Palestinian Authority forces late last year, and since then, Muhaisen said, they have succeeded in improving order. Such progress is critical to ongoing peace talks between Israel and the Palestinian Authority, which are aimed at establishing a formula for Palestinian statehood by the end of the year.

But while Palestinian Authority forces control Nablus by day, the Israeli military still sweeps in most nights. In the past two weeks, Israel has sent nightly convoys of trucks and jeeps into the city center so troops can bang down doors at organizations with suspected links to Hamas, collect evidence and leave behind closure notices. More than a dozen offices have been targeted.

At the Islamic school, teachers arrived the morning after the raid to find the building almost completely gutted. "Everything was destroyed -- my books, my papers, my exams," said Haneen Abu Aisheh, who has taught English and art at the school since it opened four years ago.

She said the school had become popular in Nablus because the average class size is between 15 and 20 students, compared to government-run schools where classes can swell to 40 students or more.

Abu Hasan, the parent and lawyer, said that while the Islamic school includes religion in the curriculum -- as do the government schools -- it does not teach students to follow Hamas's ideology.

Abu Hasan said that he and several other lawyers are challenging the closure order in court. But he is not optimistic.

"The problem is the military bases this order on secret evidence. There's nothing that we can argue with and debate," said Abu Hasan, whose work typically involves representing Palestinian prisoners, including members of Hamas. His office was raided this week.

Israel says its raids of Hamas-affiliated schools in the West Bank have turned up propaganda for the group and posters glorifying violence against Israel.

"The incitement is very obvious," said Maj. Avital Leibovich, a spokeswoman for the Israel Defense Forces. "They take advantage of very weak populations and educate those populations according to Hamas rules."

Israeli officials say the Hamas charities function on a variety of levels that all help the movement to grow: They foster goodwill toward Hamas at a time when its military and political activities, which are banned in the West Bank, have been forced underground; they give the group a powerful platform for recruitment; and they offer a convenient front for funneling money that ends up being used for military training and weapons.

But not everyone in Israel's security establishment agrees with the wisdom of the latest crackdown, arguing that acting too quickly could leave large segments of the population in need and with nowhere to turn. "There needs to be an alternative to these organizations. We can't just cut them off in one day," said one high-ranking security official, who spoke on the condition of anonymity because he was not authorized to speak publicly.

Fatah, long beset by corruption, does not provide the social services its rival does. And in a place where about half the population favors Hamas, it is difficult to find any institution in the West Bank without some sort of link to the group.

Among the organizations raided within the past week were several that said they were completely independent of Hamas, though it is impossible to know the political affiliation of all their board members and donors.

"This association doesn't have any political connections. It's only involved in charitable work," said Ali Basyouni, chairman of an organization that provides medical and educational services to refugees in Nablus's sprawling camps.

Nonetheless, Israeli soldiers raided the group's office last week, seizing computers and leaving a spray of files scattered on the floor beneath a prominently hung portrait of Palestinian Authority President Mahmoud Abbas.

Across town, the Nablus Mall had also been hit. Although not a charity, the mall is said by Israel to be owned by a company with ties to Mayor Adli Yaish, a Hamas politician who is in an Israeli prison.

The five-story mall was Nablus's first, and with its skylights, escalators and polished marble floors, it would not be out of place in a U.S. suburb. The shops feature children's toys, home furnishings and low-cut women's dresses.

While Israel says the mall helps fund Hamas's military campaign, the merchants say that most own their own shops and that the closure of the mall on Aug. 15 -- as Israel is threatening -- will ruin them.

"Everything that I had, I've invested in this shop. It's my livelihood," Baha al-Baz, 23, said as the stuffed cartoon characters Winnie the Pooh and Tweety Bird peered over his shoulder. "All of the owners just come here to work. It's not Fatah. It's not Hamas. It's a shopping mall."