In the intense war of words over the Israel-Gaza war, a particular phrase has popped up repeatedly. At protests, on fliers and in some mainstream publications, it is common to see Israel described — or more likely, assailed — as a “settler-colonial” state.

The concept of settler colonialism originates in academia, where its use has surged over the past two decades, whether in case studies of particular places or sweeping master narratives that purport to explain everything since Columbus. It has also been widely taken up on the activist left, invoked in discussions of gentrification, environmental degradation, financial capitalism and other subjects.

The term “settler colonialism” may combine two words that are very familiar. But in combination, the term can land as a moral slander — or worse.

Those who call Israel a settler-colonial enterprise see a country formed by waves of Jewish arrivals who pushed Arab inhabitants out to create an exclusive ethnostate. To others, that is a gross distortion that redefines refugees as oppressors and ignores the long history of the Jewish diaspora’s attachment to its ancestral land — as well as the continuous existence of a Jewish community whose ancestors never left.

More broadly, critics say that the embrace of the term reflects a dangerously simplistic view of history — a kind of “moral derangement,” as Adam Kirsch, an editor at The Wall Street Journal, wrote recently, which justifies violence and rests on “the permanent division of the world into innocent people and guilty people.”

But for many scholars, settler colonialism is a serious and useful analytic concept. For them, it is meant not to condemn or delegitimize, but to illuminate similarities and differences across a wide range of societies, past and present.

“I believe there is purchase to the term,” said Caroline Elkins, a Pulitzer Prize-winning historian at Harvard and a co-editor of the 2005 collection “Settler Colonialism in the 20th Century.” “From a strictly empirical perspective, there are colonies — and in some cases, nations today — that were founded on the premise of sending settlers to different locations in the world.”

But amid today’s fierce polemics, even scholarly discussion of the term is fraught. “We have all become very cautious about how we use it,” Elkins said, “out of fear that we’ll be misunderstood.”

Historians have identified many forms of colonialism. Some involve trade or natural resource extraction managed from afar. Others involve systematic exploitation of a local labor force, with the profits sent back to the imperial center.

While uses differ, settler colonialism generally refers to a form of colonialism in which the existing inhabitants of a territory are displaced by settlers who claim land and establish a permanent society where their privileged status is enshrined in law.

The concept emerged out of postcolonial studies, which arose in the 1960s and ’70s as a way of understanding colonialism from the point of view of the formerly colonized across the world. Among the key thinkers was the Afro-Caribbean psychiatrist and philosopher Frantz Fanon, whose classic 1961 book “The Wretched of the Earth” argued that colonized people were justified in using violence to throw off their oppressors.

Fanon, who wrote in French, did not use the term “settler colonialism.” But his ideas are echoed in today’s conversations, said Adam Shatz, the author of “The Rebel’s Clinic,” a new biography of Fanon published this week.

But Fanon’s ideas, he said, have also been distorted, particularly by those who have emphasized his justification of violence. For Fanon, he said, decolonization did not involve a simple act of violent “cleansing,” but a social transformation that would reorder the relations between colonizer and colonized.

“It does not necessarily mean that the solution to a situation of colonial injustice is for the colonizers to simply pack up their bags and leave,” he said.

Many scholars trace the current sense of “settler colonialism,” and its exploding influence in academic circles, to Patrick Wolfe, a British-born Australian scholar and the author of the 1998 book “Settler Colonialism and the Transformation of Anthropology.”

In a tribute to Wolfe after his death in 2016, the scholar Lorenzo Veracini wrote that Wolfe said he had included the phrase in the title at the last minute, at the urging of his publisher. (It occurs infrequently in the book itself.)

“Like the British, who had supposedly set up an empire without really wanting to,” Veracini wrote, “this committed anti-imperialist scholar kick-started a scholarly field in a fit of absent-mindedness.”

Wolfe’s densely theoretical book, which focused on Australia, where white settlers styled themselves as arriving in “empty land,” included two much-quoted phrases. “Settler invasion,” Wolfe wrote, “is a structure, not an event.” That is, it is not a historical episode that ends, but a set of relationships embedded in the legal and political order. And it rests, he wrote, on “the logic of elimination.”

“It’s ‘a winner take all,’ a zero-sum game,” Wolfe told an interviewer at Stanford in 2012, “whereby outsiders come to a country, and seek to take it away from the people who already live there, remove them, replace them and displace them, and take over the country, and make it their own.”

The term gained ground across various disciplines, sometimes shorn of its harder-edged absolutes, like the idea that it always involves an effort to eliminate existing populations. In 20th-century instances, those populations often remained a majority, albeit a dominated one.

The essays in “Settler Colonialism in the 20th Century,” the 2005 collection edited by Elkins and Susan Pedersen, looked at examples including various European settlement projects in Southern Africa, French colonization of Algeria, Japanese expansion in Korea and Manchuria in the 1930s, Nazi plans to resettle ethnic Germans in occupied Poland, and Jewish immigration to Palestine between 1882 and 1914.

That book did not discuss the United States. But the concept also has deep roots in Native American studies, while also being in some tension with it.

Ned Blackhawk’s book “The Rediscovery of America: Native Peoples and the Unmaking of U.S. History,” which won last year’s National Book Award for nonfiction, refers frequently to settler colonialism. But Blackhawk, a professor of history at Yale, has also expressed reservations about the concept’s “totalizing features.”

“As an idea that emphasizes ‘Indigenous elimination’ as one of its central features, it often minimizes the agency, adaptation and resurgence of Native American communities,” Blackhawk said in an interview with Mother Jones last year.

Since 2005, the term “settler colonialism” has continued to spread in scholarly circles, migrating into political science, literary studies, musicology and many other fields.

Aziz Rana, a political scientist and professor of law at Boston College Law School, is the author of the 2010 book “The Two Faces of American Freedom,” which argues that settler colonialism lies behind both the nation’s enduring racial hierarchies and the emancipatory possibilities of its political tradition.

When he was in graduate school in the early 2000s, Rana said, the concept was used by some scholars of empire. But it remained “really at the edge” of fields like American history and American political science.

That changed, Rana said, as scholars of the United States began to embrace new thinking about race, slavery and Native Americans, and as the Iraq war and its aftermath forced a rethinking of the traditional consensus that the United States was not an empire.

At the same time, the term migrated out of the academy and was embraced by the activist left, where it became useful for drawing connections across a broad range of issues.

“Movement activists have very consciously sought solidarities across efforts to confront anti-Black racism, Native American dispossession and immigrant mistreatment,” Rana said. “The concept has been a powerful way of showing the links across these experiences.”

But seeing settler colonialism as inherently connected with “whiteness,” some scholars argue, is simplistic.

In a recent essay in the online magazine Aeon, Lachlan McNamee, author of the new book “Settling for Less: Why States Colonize and Why They Stop,” argues that settler colonialism is not just a “historical Western evil,” perpetrated by white nations against Black and brown people.

McNamee, a political scientist, cites Japan’s invasion in the 1930s of northeastern China (where it used the promise of free land to lure 270,000 Japanese settlers to the newly created state of Manchukuo, or Manchuria), as well as Indonesia’s resettlement of 300,000 farmers in West Papua in the 1970s and ’80s, following Indigenous uprisings. (Scholars have also cited the example of Liberia, which was colonized after the U.S. Civil War by emancipated African Americans, who became the dominant elite.)

Online maps depicting settler colonialism today “almost exclusively depict areas settled by Europeans,” McNamee writes. “Colonized peoples in the Global South have experienced a double erasure: first by settlers and second by settler colonial studies.”

Nowhere is the idea of settler colonialism more charged than in discussions of Israel, whether it is used to describe Israel’s current settlements in the West Bank or the processes that led to the founding of the Jewish state itself in 1948.

A version of the argument appeared as early as 1967, in the French Marxist scholar Maxime Rodinson’s book “Israel: Fait Colonial?” (It was published in English in 1973 as “Israel: A Colonial-Settler State?”)

More recently, Rashid Khalidi, a prominent Palestinian American historian at Columbia University, drew on it in his best-selling 2020 book “The Hundred Years’ War on Palestine: A History of Settler Colonialism and Resistance, 1917-2017.”

The concept, he said in an interview, was present in Palestinian writing of the 1920s and ’30s, even if non-Arabic-speaking scholars were not reading it. He said it also reflected the self-conception of early Zionists, who primarily came from Eastern Europe.

“This was a movement that saw itself as operating as a colonial project” under the sponsorship of the British, who controlled Palestine from 1918 to 1948, Khalidi said. “They made no bones about it until World War II. They called themselves settlers. They described their process as colonization.”

But to many Jews, connecting Israel with settler colonialism is anathema given the Jewish people’s historical connection with the land. The notion also gets mixed reactions among Israel’s left-leaning “New Historians,” who have challenged the country’s traditional nationalist narratives.

In a recent interview with The Los Angeles Times, Avi Shlaim, the author of “The Iron Wall: Israel and the Arab World,” said that “Palestinians have had the misfortune to be at the receiving end of both Zionist settler colonialism and Western imperialism, first British and then American.”

But in an email, Tom Segev, whose books include “One Palestine, Complete: Jews and Arabs Under the British Mandate,” said that “colonialism is irrelevant to the Zionist experience.”

Zionists were motivated primarily by “a historical vision for their future identity in what they considered their ancient homeland” rather than an “imperial strategic or economic vision or a desire to dominate the local population.”

Besides, Segev said, “most Jewish immigrants in Palestine and Israel did not come as Zionists but as refugees.”

For some historians, it is not a yes-or-no question.

“Are Jews ‘indigenous’ or settler colonialists in Palestine?” the scholar Barnett R. Rubin wrote in a recent essay in Boston Review. “They are both.”

“Today’s settlers in the West Bank and the Golan Heights could indeed return — their ‘mother country’ is Israel — but the same is not true of the citizens of Israel as a whole,” he wrote. “They cannot return to the scenes of the Holocaust or to the Arab and Muslim states that expelled them.”

For the United States, the idea of settler colonialism may not carry the same explosive charge. While the phrase is still outside the political mainstream, the idea lies behind the land acknowledgments — which recognize and name the Indigenous inhabitants of places — that have become commonplace across universities and cultural institutions.

To some observers, including some Indigenous critics, those acknowledgments are just toothless moral theater. But Rana, of Boston College, argues that taking the idea of settler colonialism seriously allows for a more honest view of how the United States — not just its territory, but its enduring legal and political structures — was formed.

Still, he cautions against treating settler colonialism as a historical master key.

“This lens doesn’t tell you everything you need to know,” Rana said. “But it allows you to see something that you otherwise would not be able to see.”