YESTERDAY'S attack on an Israeli bus by two Palestinian gunmen, which bore the hallmarks of the radical Islamist Hamas organization, appears to bolster an opinion increasingly shared by both Palestinians and Israeli security officials: that Hamas is practically impossible to destroy.
Three Israelis were wounded when two Palestinians opened fire on a Jerusalem bus early Thursday morning. The gunmen - along with the Israeli driver of a car they had hijacked for their escape - were killed soon afterward by soldiers at a roadblock.
Although no group had claimed responsibility for the attack by press time, Israeli Prime Minister Yitzhak Rabin blamed it on Islamic extremists, and the operation's daring and violence suggested it was the work of Hamas, striking in defiance of three heavy blows the organization has suffered in the past six months:
* Last December, 415 alleged Hamas political leaders were deported to South Lebanon, and some 1,200 suspected Hamas militants were arrested.
* A month later, Israeli agents arrested four Palestinian-Americans said to be couriers ferrying $600,000 to Hamas members in the occupied territories.
* In early June, authorities announced they had caught 124 more Hamas militants, including the cell that killed an Israeli border policeman named Nissim Toledano. His death had prompted the mass deportation.
These steps have weakened Hamas and its military wing, the Izzadin al-Qassam brigade, Palestinian analysts and Israeli security officials agree. But they have by no means uprooted them.
"Hamas can rebuild itself more quickly than secular groups," argues Iyyad Barghouti, a Palestinian political scientist at An Najah University in Nablus, on the West Bank, who has studied Hamas closely. "They always have young people ready to sacrifice themselves."
Israel's secret police, the Shin Bet, is casting dragnets through that pool of replacements with growing care, but it is a long and possibly endless task, as a senior Shin Bet official acknowledged at a recent briefing for journalists.
When one Hamas leader was deported last December, he said, "other people came instead of him, and we took the other people who came after him, and so on and so on."
The pace of attacks by Hamas gunmen on Israelis has slowed over the past six months. "All the steps taken against [Hamas] have disrupted their operations and made life very difficult for them," says Army spokesman Lt. Col. Moshe Fogel.
But "maybe they are in a phase of reconstructing themselves" suggests Hader Sawarnek, dean of Religious Studies at An Najah University.
Attracting new recruits to step into the shoes of Hamas activists who have been arrested, deported, or killed seems a relatively easy task. The gunmen of the Izzadin al-Qassam brigade are only the tip of the Hamas iceberg, which is mainly a political organization - the Palestinian branch of the Muslim Brotherhood - whose opposition to the faltering Middle East peace talks has won it support from an estimated 30 percent to 40 percent of Palestinians.
Outlawed in June 1989, Hamas' political activities have continued unchecked; the group regularly distributes its leaflets and organizes meetings in the West Bank and Gaza Strip.
"Hamas is not a traditional political organization, it is more of an idea around which people gather," explains Dr. Sawarnek.
That makes it especially hard to control, according to the Shin Bet agent. "It is the decision of one hour, half an hour, that you are in the political part and you are moving to the military part," he said. "We have to know very well when this will happen, and it is very difficult for us to know exactly."
The four men who killed Toledano clearly illustrate this elusive transformation. A plumber, a journalist, a municipal gardener, and a hospital cleaner, all students of Islam at Jerusalem religious colleges, spontaneously decided among themselves to kill Israeli soldiers and policemen, according to the Shin Bet agent.
Only after they had run Toledano over in their car, and stabbed him to death, did they approach a Hamas member for money and guns, he said.
At an operational level, divided into cells answering to leaders based in Jordan, according to both knowledgeable Palestinians and Israeli security officials, Hamas gunmen are more professional than their counterparts in the Palestine Liberation Organization (PLO).
Though PLO armed cells are more numerous, and carry out more attacks on Israeli soldiers, according to Colonel Fogel, "in terms of casualties, Izzadin al-Qassam has the majority. They are more effective in inflicting casualties."
Israeli security officials acknowledge that despite their recent drive against Hamas, the organization remains active. "I am sure they will try to act against us in the near future, and it depends on us whether we will be able to stop their activities," the Shin Bet agent predicts.