Anti-Semitism is on the rise and must be confronted.Credit: Robert Cohen/St. Louis Post-Dispatch/TNS/Getty

A dark shadow is stalking the land. Anti-Semitism is once again showing itself and must be confronted head-on and stamped out wherever it is found. Discrimination against any individuals and groups goes against the values of science, human decency and this journal. Sunlight remains the best disinfectant, and one of the places where the infection of anti-Semitism still thrives is on some university campuses. If researchers who work there are not aware of this and angry about it, then they have not been paying sufficient attention.

There are many examples and many responses. Just last week, South Carolina took another step towards a law that would make it the first US state to set a legal definition of anti-Semitism. Supporters of the move argue that it is needed to help university administrators to combat a rising tide of hate against Jewish staff and students. Critics say it impinges on free speech. That this is being discussed at all in 2018 speaks volumes.

One does not have to delve too deeply into modern international politics to find clear examples of a renewed and ugly mood of hostility towards Jews. The prime minister of Hungary, Viktor Orbán, secured a fourth term in office earlier this month on an aggressively nationalist ticket widely criticized for anti-Semitic images and messages. And last week saw the grim spectacle of British MPs standing in Parliament and reading out some of the intolerable anti-Semitic abuse they have received as part of a highly unusual debate on the subject.

It would be surprising if this political climate did not embolden anti-Semites on campus. Reliable numbers are hard to come by. In a report last year, the European Union Agency for Fundamental Rights pointed to gaps in data about anti-Semitic incidents across the continent, which it intends to address with a survey later this year. But some estimates do indicate that there has been a surge in places, including schools and universities.

In the United States, the Anti-Defamation League reported in February, such incidents on university campuses increased by 89% in 2017, to 204. Surveys in the United States and the United Kingdom highlight that many Jewish students find the atmosphere on campus intimidating. This is hardly surprising, given that one of the most common offences is to draw a swastika on a wall.

Anti-Semitism — prejudice and violence against individuals and communities — is distinct from legitimate criticism of Israeli policy. It is perfectly possible to argue the rights and wrongs of international politics without hate speech.

The following is a widely accepted definition from the International Holocaust Remembrance Alliance: “Anti-Semitism is a certain perception of Jews, which may be expressed as hatred toward Jews. Rhetorical and physical manifestations of anti-Semitism are directed toward Jewish or non-Jewish individuals and/or their property, toward Jewish community institutions and religious facilities.”

According to this definition, examples of anti-Semitic behaviour include (but are not limited to) furthering the myth that Jews are engaged in a shadowy conspiracy to control events, and holding Jews collectively responsible for the actions of the government of Israel. It should not need saying that this is as preposterous as holding Muslims collectively responsible for the actions of the Syrian government.

Nature has a long history of highlighting and confronting anti-Semitism. In an editorial in December 1935, this journal warned that an “anti-Semitic clique” was trying to seize control of the Germany-based Astronomical Society (Nature 136, 927–928; 1935). Less than a month later, we noted that discrimination against Jews and other “non-Aryans” meant that “Germany stands condemned as guilty of a persecution no less barbarous and an intolerance as rigid and as crass as any that figure in the annals of the Middle Ages” (Nature 137, 16; 1936).

It is sad and worrying that we feel the need to highlight the point again. But we are confident we can rely on Nature’s readers to challenge anti-Semitism whenever and wherever it occurs — in their universities, on campus, at social occasions, or on the street — just as we can rely on readers, as we have frequently urged them, to challenge those who express their hatred of people of colour, women, Muslims, immigrants, the gay and transgender community and many others.