(RNS) — In his initial response to the rampage of slaughter in Israel by Hamas, President Joe Biden said, “There are moments in this life — and I mean this literally — when the pure, unadulterated evil is unleashed on this world.” What Hamas did, he reiterated, was “an act of sheer evil.”

But how does this evil come to be unleashed? Calling Hamas “a terrorist organization” begs the question. Any adequate explanation must reckon with the organization’s religious character and motivation.

Hamas is devoted to military jihad of a distinctive kind — armed struggle, not (as in the Middle Ages) to expand Islamic territorial control, but to restore territory it once controlled. As its 1988 covenant declares, “The day that enemies usurp part of Moslem land, Jihad becomes the individual duty of every Moslem. In (the) face of the Jews’ usurpation of Palestine, it is compulsory that the banner of Jihad be raised.”

While the organization’s 2017 statement of “general principles and objectives” makes no mention of jihad as such, this jihadist aim remains intact — and not only because the 1988 covenant has never been disavowed. Calling Palestine an “Arab Islamic land” that is “blessed” and “sacred,” the statement asserts the right of the Palestinian people “to their entire land” against “the usurping Zionist entity.” (The latter term substitutes for “the Jews” in the 1988 document.)

In international affairs, a country’s claim to territory it believes it once possessed and is entitled to again is known as irredentism — from the Italian word for “unredeemed.” We might call what motivates Hamas “spiritual irredentism,” a drive to restore territory to one’s own real or imagined prior religious control.

This species of motivation is hardly restricted to Islam. The Crusades were holy wars created to redeem territory — the Holy Land — once under Christian control. After gaining access to the Temple Mount in Jerusalem, the first crusaders went berserk. “In this temple 10,000 were killed,” wrote the Frankish priest Fulcher of Chartres. “None of them were left alive; neither women nor children were spared.”

In 1995, 7,000 Bosnian Muslim prisoners were slaughtered by Bosnian Serbs in a war whose irredentist claims to Bosnia were cast as a war of religion by Serbian Orthodox as well as political leaders. Today, in Vladimir Putin’s irredentist war against Ukraine, the genocidal crimes perpetrated by Russian soldiers are taking place under the aegis of Moscow Patriarch Kirill’s promise that those who die in the war will be cleansed of all their sins.

In Judaism these days, spiritual irredentism is the province of religious Zionists who have settled on the West Bank since it was captured during the Six Day War of 1967. Impelled by a desire to hurry the arrival of the Messiah, they seek to make the territory they call “Judea and Samaria” an official part of Israel proper.

Not infrequently, they have perpetrated violence against Palestinians, most notoriously in 1994, when American-born physician Baruch Goldstein opened fire with an assault rifle on Palestinian Muslims praying in the Cave of the Patriarchs in Hebron, killing 29 people, several as young as 12 years old, and wounding 125. 

Since February, the official in charge of civilian affairs in the West Bank for the Netanyahu government has been Bezalel Smotrich, the head of the religious Zionist Party whose 2017 “Decisive Plan” amounts to a Jewish version of Hamas’ 2017 statement. If you want to watch Smotrich literally beating the drums for the Messiah, check out this video. 

Bezalel Smotrich drumming home the Messiah. pic.twitter.com/dlNEY9bIkp

— Mike (@Doranimated) October 6, 2023

Efforts by religious Zionists to expand Israeli control over the West Bank by violent means have reportedly accelerated since the Hamas massacre. So it goes.

By the foregoing I do not mean to suggest that all spiritual irredentist claims are equivalent or even wrong. Or that all acts of religious violence intended to restore territorial control are equally abhorrent. Or that Hamas should in any way be let off the hook for what it perpetrated against Israeli civilians on Oct. 7.

I mean to suggest that when spiritual irredentists go to war, be prepared for evil to be unleashed.