RAMALLAH, West Bank ? It took just a quick telephone poll among regional leaders of the Al Aqsa Brigades militia to reach an unanimous decision despite a truce ordered by Yasser Arafat, they would avenge one of their own killed in a bombing blamed on Israel.

Six shooting and bombing attacks later, 11 Israelis and an American were dead, the United States called off Mideast mediation efforts and President Bush sharply rebuked the Palestinian leader for not fighting terrorism.

Militants increasingly appear to be setting the Palestinian agenda, and despite the world’s growing impatience with him, Arafat has not tried to crush the militias that attack Israeli civilians whether those run by political rivals Hamas and Islamic Jihad, or the Al Aqsa Brigades linked to his own Fatah movement.

Is Arafat, then, behind the violence?

Israel says yes, he is a terrorist; his Dec. 16 truce declaration was a sham, intended to deflect international pressure and buy time for his fighters to regroup and rearm. A 50-ton Iranian weapons shipment intercepted en route to the Gaza Strip last month is proof of Arafat’s intentions, Israel says.

Arafat’s aides say Israel disrupted a good-faith effort at cease-fire. Arafat can’t be expected to act and possibly risk armed confrontation with the militias when his headquarters are besieged by Israeli tanks, his security forces are hobbled by Israeli strikes and there is scant hope Israel will meet even the Palestinians’ minimal demands for peace, they say.

Reluctant efforts

A look at the Palestinian command structure reveals only a half-hearted effort by Arafat, based on persuasion rather than coercion, to protect the truce. Arafat’s reluctance appears tied to widespread public sympathy for the militants; 92 percent back shooting attacks on Israeli soldiers and settlers in the West Bank and Gaza Strip, according to one recent poll.

In the latest deterioration, a key event was the Jan. 14 killing of Raed Karmi, leader of the Al Aqsa Brigades in the West Bank town of Tulkarem who had boasted of killing two Tel Aviv restaurateurs last year. He died in a bomb explosion widely attributed to Israel.

Karmi’s death had been preceded by more than a month without Israeli civilian deaths the longest such period since fighting erupted in September 2000.

Israel claimed Karmi was planning attacks, while the Palestinians said Ariel Sharon had Karmi killed to torpedo a truce that, if maintained, would have forced the Israeli prime minister to freeze Jewish settlement activity as part of a U.S.-backed peace plan.

Hussein al-Sheik, Fatah leader in the West Bank, said he was asked by Arafat after Karmi’s death “not to have any revenge attacks.”

Al-Sheik was noncommittal and Arafat didn’t press an approach Israel says amounts to wink-and-a-nod approval to commence violence.

“I told (Arafat) that this is difficult, that I cannot tell people not to take revenge for Raed Karmi,” al-Sheik said in an interview. He said he told militia leaders of Arafat’s request, but added that “I didn’t forbid” revenge attacks.

A will of their own

The Al Aqsa Brigades, formed three months after the outbreak of the fighting, include several hundred gunmen. Most are Fatah loyalists.

The militia has carried out scores of shooting attacks on Israelis in the West Bank and Gaza, but until now had largely refrained from attacks inside Israel.

Some cells are financed by Fatah politicians hoping to enhance their clout, and Israel has accused another Fatah leader, Marwan Barghouti, of ordering attacks.

One militia leader, who would only give his nom de guerre of Abu Mujahed, said he received a weapon as a gift from a senior Palestinian security official, to ensure loyalty.

Abu Mujahed, 31, who says he helps recruit members and oversees weapons training, said that after Karmi’s killing he polled militia commanders to decide on a response.

“Everybody said the cease-fire is just a joke,” said Abu Mujahed, a Czech-made mini-machine gun stashed in his laptop computer case. “We decided on our own” to take revenge, he added.