Last week, Alexander Heifler, a 26-year-old living in Hoboken, New Jersey, was arrested over an alleged plot to firebomb the home of Palestinian activist Nerdeen Kiswani.

Heifler belonged to a Zionist organization called the JDL 613 Brotherhood, a little-known group that draws inspiration from one of the most notorious Jewish organizations in the U.S. in recent decades — the Jewish Defense League.

What is the Jewish Defense League, how is it connected to current Zionist violence and attacks on Palestine activism, and what is its enduring legacy? Below is a short explainer.

The Jewish Defense League, or the JDL, is a far-right, pro-Israel organization that was founded in 1968 by Rabbi Meir Kahane, amid racist backlash throughout New York City.

Kahane called for every Jew to be armed and popularized the slogan “Never Again.”

“To turn the other cheek is not a Jewish concept. Do not listen to the soothing anesthesia of the establishment,” he declared. “They walk in the paths of those whose timidity helped bury our brothers and sisters less than thirty years ago.”

Kahane claimed that he created the JDL to protect Jews from antisemitic violence, but its members have been linked to a number of terrorist attacks, murders, and attempted killings.

Its early days were defined by targeted attacks on Soviet establishments, over the country’s alleged antisemitism and ban on Israel emigration.

According to the Southern Poverty Law Center (SPLC), the group carried out 5 acts of terrorism in 1970 alone, taking over the East Park Synagogue in Manhattan twice to protest the United Nation’s Soviet Mission, dumping blood on a Soviet diplomat, and and planting a smoke bomb in a Carnegie Hall during a performance by the Soviet orchestra.

On February 25, 1994, JDL member Baruch Goldstein, a JDL member opened fire on praying Muslims in Hebron’s Cave of the Patriarchs, murdering 29 and injuring 125, before he was killed by authorities.