Over the weekend, Israeli authorities arrested nine Jewish settlers in the West Bank. It was a crackdown, the Israeli newspaper Haaretz said, on "Jewish terrorism." The men were wanted in connection with Jewish extremist movements in the West Bank.

A few days earlier, a group — believed to be Jewish extremists — attacked the house of a Palestinian family in the West Bank, setting it on fire and killing 18-month-old Ali Dawabsheh inside. Israelis were disgusted at the attack, with leaders, including President Reuven Rivlin, speaking out against the attack and against "Jewish terrorism." It's unknown if these arrests are directly linked to that attack, but they are part of the Israeli backlash against Jewish extremism.

These extremists target Jewish Israelis as well. About a week ago, security officers who protect Rivlin notified the Israeli police that Rivlin had been receiving death threats. The threats, they said, had been sparked by Rivlin's Facebook post condemning Dawabsheh's murder.

Israel's Jewish extremism problem is real: the only Israeli prime minister ever to be assassinated in office, Yitzhak Rabin, was killed by a Jewish man enraged by Rabin's negotiations with the Palestinians. The scale of the problem ebbs and flows over time, but it comes from the fundamental tension in Israeli society: its dual identity as both a liberal, tolerant democracy that is also a fundamentally exclusive Jewish state. And today, there's nowhere that tension manifests more clearly than in the occupation of the West Bank.

Modern Jewish terrorism began with settlements, but represents something bigger than that

Jewish terrorism in the Holy Land is relatively rare, but its history predates the state of Israel. Most famously, the Zionist militia Irgun bombed the King David Hotel in 1946, the hotel housing British administrative authorities. The Irgun also bombed Arab-populated buses, markets, and population centers, killing scores of civilians. These sorts of attacks had a number of purposes: to drive the British out of what was then British-controlled Palestine, secure Jewish control over the land, and retaliate for Arab killing of Jews.

But Jewish terrorism as we know it today is ideologically different — and more religious — than those early Zionist attacks. This newer phenomenon has its roots in Israel's 1967 war with its neighbors, which ended with Israel taking control over, among other territory, East Jerusalem and the West Bank.

"The era of Jewish terrorism began after the 1967 War," scholars Ami Pedahzur and Arie Perliger, authors of a book on the subject, write.

Israel's conquests transformed Orthodox Jewish identity, which had previously been partly apolitical. For some Jews, this awakening was messianic: a belief that Jewish control of the West Bank marked the beginning of the End Times. For others, it was religious-nationalist: a notion that God had promised all of this land to the state of Israel and had finally delivered.

These ideas flourished in small, insular communities — particularly in the new Jewish settlements in the West Bank, which was occupied by the Israeli military. Inside these communities, a radical fringe decided that protecting Jewish land wasn't a task the Israeli state could be trusted to handle alone: It was something they needed to take into their own hands. The most exclusive vision of Israeli Jewishness, in other words, bred an even more exclusive iteration.

"The majority of the religious Zionist settler community opposes terrorism against Arabs," Georgetown University's Daniel Byman writes. "Yet most of today's Jewish terrorists emerge from this milieu, and its story is bound up in that of Jewish terrorism."

In 1980, the Jewish Underground, a splinter from the settler-religious movement Gush Emunim, set off car bombs that seriously injured the Palestinian mayors of Ramallah and Nablus. In 1994, Baruch Goldstein walked into the Cave of the Patriarchs in Hebron and opened fire on Palestinian worshippers, killing 29. In 1995, religious nationalist Yigal Amir walked up to Prime Minister Rabin and shot him twice, killing him.

More recently, some West Bank settlers have launched hundreds of "price tag" attacks, mainly targeting Palestinians and Israeli Defense Forces property — culminating in the recent killing of Dawabsheh.

The extremist subculture

The key to understanding these radicals, according to Pedahzur and Perliger, is as a subculture. They reject mainstream Israeli society — its democratic values and notion of synagogue-and-state separation — and see themselves and their communities as guardians of authentic Jewish values. Their violence ebbs and flows because it's often reactive: When extremists see Arabs or mainstream Israeli society as threatening their vision of Jewishness, they take action.

Most often, the spark is an uptick in the Israel-Palestine conflict, or some compromise by the Israeli government. Pedahzur and Perliger's data shows spikes in Jewish terrorism in several cases where Israel had been seriously considering land compromises, or was at open war with the Palestinians. The Jewish Underground appears to have formed as a direct response to Israel's 1978 peace treaty with Egypt, which returned the Sinai, previously conquered by Israel, to Egyptian control.

The movement's rejection of peace, and its apparent belief that peace itself is a betrayal of their very Jewish identity, comes through in this chilling statement to police from Yigal Amir, who assassinated Prime Minister Rabin in 1995:

[The Arabs are] our antithesis in every way. We can't live peacefully with them. For three years they [Rabin's government] have imposed their outlook in a way that's created new concepts. I mean, peace has received a new meaning. The word "peace" is, to me, first of all peace within the nation. You must love your [own people] before you can love others.

For people like Amir, Israel is a state that is first and foremost for Jews. Any attempt to compromise with the Palestinians is a threat to this vision of what Israel stands for — and hence needs to be snuffed out.

How Israel treats Jewish terrorism, and what it says about Israel

Mainstream Israeli society, to its credit, has consistently rejected these attacks and the attackers. After Goldstein's attack on the Cave of the Patriarchs, Israel banned Kach — an extremist political party with which Goldstein had once run for office, and that had issued a statement supporting his attack. When extremists in Hebron built a shrine to Goldstein, the Israeli government bulldozed it.

This shouldn't surprise anyone. Given Israelis' long and deadly experience with Palestinian violence, terrorism holds a special place of horror in the Israeli imagination. They see refraining from targeting civilians as part of what makes Israelis different from — and better than — Palestinian militants. So when Jews do it, it's a real shock.

"We are determined to vigorously fight manifestations of hate, fanaticism and terrorism from whatever side," Prime Minister Benjamin Netanyahu said after the Dawabsheh killing. "We deplore and condemn these murderers. We will pursue them to the end. ...They name public squares after the murderers of children. This distinction cannot be blurred or covered up."

And yet, Israeli security services have done relatively little to crack down on Jewish extremists. A report by the human rights group Yesh Din found that only 7.6 of Palestinian complaints about settler violence result in indictments.

Byman, the Georgetown scholar, points to what he says is a "double standard" between the way Israel treats Jewish and Palestinian terrorists. The sort of harsh punitive measures it tends to apply to Arab terrorism generally aren't employed in the Jewish case:

Administrative detention is rarely ordered. Settler homes are not destroyed if a member commits a terrorist act. Israel does not impose restrictions on Jewish religious institutions that turn out militants and violent propaganda. Some rabbis who justify violence even receive government salaries. ... Unlike their Arab counterparts, [Jewish terrorists] wait out Shin Bet [Israel's FBI], knowing that interrogators are less aggressive towards their own. Even when convicted, Jewish extremists receive lenient sentences.

There's a plan to change some of this in the wake of the Dawabsheh attack. But this historical norm is striking given the deep and widespread revulsion that most Israelis feel toward Jewish terrorists; it's not as if they're sympathetic. It speaks to the basic dilemma Jewish terrorism poses for Israel. On the one hand, these people are terrorists — they kill Jews and Arabs alike, and do so explicitly as an attack on Israel's democratic institutions.

Yet at the same time, these terrorists are Jews in a Jewish state. And not only are they Jews, but even if their actions are driven in part by anti-liberal and anti-democratic ideas anathema to the Israeli state, they are also driven by ideas that are not so marginalized. The ideas that Israel shouldn't compromise on territory or treat Palestinians or Arab Israelis equally are, to varying degrees, positions that exist within the mainstream discourse. Only a tiny fringe uses violence, but that fringe is embedded in a real constituency — settlers — that get angry if they feel persecuted.

"Because Israeli politicians are sensitive to any perception that they are targeting settlers and their supporters," Byman writes, "they are unlikely to act preemptively" against Jewish terrorists.

This, Pedahzur believes, points to an "inherent tension" within the Israeli state today: for instance, curricula in the education system that promote the state's Jewish character at the expense of its democratic one. That tension comes though in the degree to which the state does or doesn't go after Jewish terrorism.

"The non-liberal and ethnic characteristics of the State of Israel have held sway over the formation of almost all the social realms of life in this country," he writes. "These characteristics are inseparable from the [response to Jewish terrorism]."

This odd juxtaposition of how Israelis respond to Jewish terrorism — popular anger and official neglect — reflects the country's larger, conflicted identity. Jewish extremists are a threat to Israel's liberal and democratic character, but they come, at least in part, from a part of its Jewish identity that's not easily destroyed: its sense of itself as an inherently Jewish, and thus exclusive, state. Even if individual terrorists are arrested, or cells are broken up, the broader set of ideas that contribute to Jewish extremism can't be eliminated by force.