According to a medieval Irish chronicle, the first Jews to come to the island arrived in 1079 but were promptly turned away. Only in the 19th century did Ireland gain a significant, if always small, Jewish population. Aidan Beatty and Dan O’Brien write:

At its demographic height, [just after World War II], the Irish Jewish community numbered about 4,000; one tenth of 1 per cent of the total population of Ireland (north and south). Hardly a major aggregate. And yet, at that time, Jews were the only sector of the populace whose origins lay outside of Britain and Ireland; the community had long been a noticeable presence in Dublin. In 1908, for instance, the charter meeting of a Judeo-Irish Home Rule Association . . . was the cause of noticeable controversy in Ireland and within the British Jewish community; should Irish Jews remain a loyal subset of their co-religionists on the other side of the Irish Sea or should they throw their lot in with nationalists [in Ireland]?

A desire to prove their nationalist bona fides and thus to prove that they are “real” Irish would endure within the Irish Jewish community. And the community’s official narratives have often downplayed the existence of anti-Semitism among Irish Gentiles.. . .

Some of the most central figures of 20th-century Irish life have been overt anti-Semites. . . . Anti-Semitic rhetoric and imagery regularly surfaced in the nationalist press before and after 1922. The IRA-backed campaign against usury in the late 1920s targeted Jewish moneylenders far more than their Gentile counterparts. Jewish industrialists who fled the Nazis and established factories in the west of Ireland in the 1930s and 40s often had to negotiate a matrix of stereotypes and negative perceptions. The sizeable numbers of Irish men who served in the Palestine Police in the same period regularly interpreted what they saw in Jaffa, Jerusalem, or Bethlehem in terms of the anti-Jewish animosities traditional to Catholicism.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.