In the wake of a deadly attack on worshipers at a Jerusalem synagogue, Israel's Prime Minister Benjamin Netanyahu invoked an incredibly loaded term to condemn what he says was Palestinian incitement to violence. The Israeli premier said the latest killings were the result of a "blood libel" against Israeli Jews, a phrase that carries with it the stigma of centuries of anti-Semitic persecution.

The past few weeks have seen an escalation of hostilities between Israelis and Palestinians living in the holy city. The Islamist militant group Hamas didn't appear to have a direct hand in Tuesday's incident, but applauded the two Palestinian attackers, who wielded knives and guns to kill at least four Israelis at a synagogue in an ultra-Orthodox neighborhood in Jerusalem.

A Hamas statement praised the action, claiming it was revenge for the recent death of a Palestinian bus driver in the city. Israeli authorities say the man committed suicide, and conducted an autopsy to prove it, but some Palestinians are convinced he was murdered by an Israeli mob.

Netanyahu and some of his political allies jumped on this and used the moment to also condemn Palestinian President Mahmoud Abbas. "Yesterday, a bus driver in East Jerusalem committed suicide. The autopsy report proves this beyond a doubt," Netanyahu is quoted saying by Haaretz. "This didn't prevent the dissemination of a blood libel that he was murdered by Jews. This incitement contributed to the despicable massacre."

Yoram Cohen, the head of the Shin Bet, Israel's top secret security service, cautioned against Netanyahu's sweeping rhetoric, insisting on Tuesday that Abbas "is not interested in terror and is not inciting to terror."

"Blood libel" is a particularly incendiary phrase. Its roots date back to antiquity, when violence against communities of Jews was justified with false rumors of Jews stealing Christian babies, eating a gentile's entrails, participating in various grisly, sordid blood rituals. There is a long history of this, as I explained in a piece for a few years ago:

The advent of Christianity forever twinned Jews with blood. In the Gospels, Pontius Pilate publicly washes his hands of the guilt of committing Jesus to death, letting the assembled Jews take on the burden. "His blood be on us and on our children," they declare in Matthew 27: 25. These were words that stuck. Christendom grew rich by encouraging pilgrimages to venerate the purported remains of saints — bones, fingers, ears — but the Jews living in its midst were often openly faulted for bloody, occult practices, all of which were false.
Medieval lore abounds with tales of Jews in towns across Europe, from England to modern-day Slovakia and lands farther east, stealing young Gentile children for blood sacrifices. Invariably, such sensational stories were told to justify mass executions and pogroms of Jewish communities. According to some histories, a 2-year-old named Simon in the Italian town of Trento disappeared in 1475 and was found in the basement of a Jewish family, his body drained of blood so that the Jews could make matzah bread for Passover. Records show that at least eight Jews in the town were subsequently executed; Simon would be canonized as a saint a century later. Fears of Jewish baby snatching were raised by the Spanish Inquisition, leading in part to the expulsion of the entire Jewish community from Spain in 1492.
These tales lingered well into the 19th century and even the 20th century, with anti-Semitism still particularly strong in stretches of Eastern Europe. But some of the first instances of occasions when governments publicly defended Jews from these "blood libels" took place in the Muslim world, with firmans, or edicts, issued as early as the 1400s by a series of Ottoman Sultans, preventing the trial of Jews on such unfounded, outlandish accusations. (Of course, the Middle East wasn't free of anti-Jewish violence. In 1910 the Jewish quarter in the Iranian city of Shiraz was sacked by rioters who were inflamed by fabricated reports that Jews had ritually killed a young Muslim girl.)

The phrase summons a deep, long and traumatic history for Jews, one which Netanyahu thinks is apt to invoke in the context of an already fraught, volatile situation in Jerusalem.

Whether he's justified to do so, it's not the first time Netanyahu has been associated with the term "blood libel." In January 2013, the Sunday Times published a whole-page cartoon, depicting the Israeli premier building a wall atop the bodies of screaming Palestinians, using mortar that appears to be the color of blood. A caption reads: "Israeli Elections… Will Cementing Peace Continue?"

The cartoon, which was intended to be a critique of Netanyahu's right-wing policies, triggered a furious backlash from Israelis and Jewish organizations overseas. It was unfortunately published on Holocaust Memorial Day, which had escaped the attention of the cartoonist and publication's editor.

"This is the stuff which historically justified hatred of Jews and led to the wholesale slaughter of Jews," a spokesman from the Anti-Defamation League said at the time.

Anshel Pfeffer, a journalist at Haaretz, countered that the cartoon wasn't "anti-Semitic in any way."

"There is absolutely nothing in the cartoon which identifies its subject as a Jew," Pfeffer wrote. "Furthermore, Netanyahu is an Israeli politician who was just elected by a quarter of Israeli voters, not a Jewish symbol or a global representative of the Jews."