They are the shock troops of the extremist fringe, giving not only financial aid but ideological comfort to right-wing religious zealots who will do anything to stop the Middle East peace process.

They are called, with scorn, the Boys from Brooklyn.

“There is now a kind of Jewish jihad (holy war) mentality here,” says Avraham Burg, a longtime member of the Knesset who was a close ally of the slain Prime Minister Yitzhak Rabin, “and it comes from the same source as Williamsburg, Brooklyn, the source that brought (Meir) Kahane into our lives.”

Rhetoric aside, it is difficult to measure the numbers or influence of diehard U.S. militants – many of them open admirers of Kahane, the fiery, racist, Brooklyn-born rabbi who was shot to death five years ago in New York.

It was in Brooklyn that a telephone hotline was set up to raise money for the legal defense of law student Yigal Amir, who shot Rabin because, he said, God wanted him to do it. Moshe Gross, 28, a part-time rabbinical student, says the hotline raised $100,000 in two days.

It was in Brooklyn, at a Coney Island synagogue, that members of a Kahane organization who gathered to commemorate the fifth anniversary of his slaying also praised Rabin’s killer as a hero. Little girls passed out leaflets that portrayed Rabin in a Nazi SS uniform, the ultimate insult.

“Rabin was bad for Jews,” says Mike Guzofsky, also known as Yekutiel Ben-Yaacov, leader of the New York cell of the extremist Kach movement.

And it was a prominent Brooklyn rabbi, Abraham Hecht, who implied in a television interview that Rabin’s murder was justified by religious law. His congregation, Shaare Zion, in Flatbush, N.Y., has asked Hecht to stay away pending an investigation. He is now in Florida.

In Israel, one of the more fiery Hebron settlers, Baruch Marzel, who inherited Kahane’s organization, is from Brooklyn.

The irony is that while many more of the people preaching or practicing violence in the name of a greater Israel have nothing to do with Brooklyn, the size, wealth and high visibility of the Jewish activist community there makes the borough a useful metaphor for defiance.

For example, Noam Federman, 26, a Kahane apostle in Hebron whose wild threats against Arabs keeps him on the security alert list, is frequently identified by Israeli authorities as a Brooklynite. In fact, he is Russian.

Some of the extremists are ultra-Orthodox rabbis who teach that the land seized by Israel after the 1967 war – the Gaza Strip, the West Bank and the Golan Heights – belongs to Israel by historic divine right and to give it up would contradict God’s will.

Some are radical immigrant settlers who embraced Kahane’s call for the expulsion – at gunpoint, if necessary – of all Arabs in Israel.

And some are the naive and impressionable Israeli-born recruits drawn to simplistic holy war theologies.

Israeli authorities say that there are only “a few hundred” extremists determined to kill, if necessary, to block the peace deal. Some settlements on the West Bank are closely identified with Brooklyn, because of their close spiritual and cultural ties with the borough. One of them, Kiryat Arba, is nicknamed “Williamsburg East.”

Kiryat Arba became a militant household name 18 months ago when Baruch Goldstein, the most infamous of all the Boys from Brooklyn, shot 29 Arabs dead as they prayed in a Hebron mosque.

Goldstein, who moved to Israel in 1983 from Bensonhurst, was beaten to death by survivors of the attack and buried as a hero in a memorial garden named for Kahane. Even now, dozens of people, including children, pause to pray there every day.

The Clinton administration has joined Israel in striking back at Jewish terrorism, by designating two Kahane movements – Kach (“thus” in Hebrew) and Kahane Chai (“Kahane lives”) – as risks to peace in the Middle East.

Last month, the Treasury Department used an executive order to locate and block a Kahane Chai bank account in New York – containing all of $203. Agents say they never expected to find sizable sums, and merely wanted to block the organization’s fund-raising in the United States.

But a University of Pennsylvania professor, who monitors Israeli extremist groups, says agents are failing to do this.

Ian Lustick says Kach fund-raising is well-known in New York and Florida, with the organization using various fronts and claiming tax-exempt status.

“This is not a great mystery,” says Colette Avital, the Israeli consul general in New York. “I know much money was raised in the past few months, a million dollars in New York recently. It worries us very much.”