ITS ORIGIN AND PURPOSE, STILL A TOTAL MYSTERY:

But for residents like Joanna Galilli, this area in northwestern Paris represents a tactical retreat. It has become a haven for many Jews who say they have faced harassment in areas with growing Muslim populations. Ms. Galilli, 28, moved to the neighborhood this year from a Parisian suburb where “anti-Semitism is pretty high,” she said, “and you feel it enormously.”

“They spit when I walked in the street,” she said, describing reactions when she wore a Star of David.

France has a painful history of anti-Semitism, with its worst hours coming in the 1930s and during the German occupation in World War II. But in recent months, an impassioned debate has erupted over how to address what commentators are calling the “new anti-Semitism,” as Jewish groups and academic researchers trace a wave of anti-Semitic acts to France’s growing Muslim population.

Nearly 40 percent of violent acts classified as racially or religiously motivated were committed against Jews in 2017, though Jews make up less than 1 percent of France’s population. Anti-Semitic acts increased by 20 percent from 2016, a rise the Interior Ministry called “preoccupying.”

—“‘They Spit When I Walked in the Street’: The ‘New Anti-Semitism’ in France,” the New York Times, Friday.

While anti-Semitism has existed in Europe for hundreds of years, often fanned by Christian churches that blamed Jews for the killing of Jesus, a large new influx of immigrants from Mideast countries into Germany has provided new sources of tension, such as the Israeli-Palestinian conflict, according to German officials and Jewish activists.

The German Interior Ministry said in its annual crime statistics survey that police received reports of 1,453 anti-Semitic incidents in 2017— four per day.

—“Jewish teens enlisted to fight anti-Semitism in Germany,” the Associated Press, today.

The other day I read an article that was first posted in December. In it, an anonymous gay Dutch guy recounted his life in the Bos en Lommer neighborhood of Amsterdam, which is a few blocks from a flat where I once lived (and where I first recognized the problem of Islam in Europe). He noted that Bos en Lommer “has undergone a dramatic transformation in the last three decades, with the most rapid change happening since 2000.” At first he felt safe there; then, biking home one day with his boyfriend, he heard antigay slurs being hurled at them by “a group of young men of Moroccan descent.” Recalling the similar taunts they’d heard back in the 1950s and ’60s (he’s obviously not a young dude), he turned to his boyfriend: “Is this really starting all over again!?”

—Bruce Bower, “Lying about Amsterdam,” at PJM today.

I’m sensing an aura of a penumbra of a perturbation of a pattern here.