Parents at the Ethical Culture Fieldston School might be wondering whether they’ve entered a time machine and exited somewhere around 1935.

In the spring, the elite Bronx private school was segregating third-graders by race and now it’s apparently teaching sixth-graders that the swastika is a symbol of peace.

As The Post reported, swastikas have been popping up all over campus this fall and a notebook was found with the words “Hitler Rocks” on the front. At least one student at the $45,000-a-year school drew a swastika during art class. A school spokesman, though, explained that the student “drew a symbol that represents peace.” The art teacher told him that the image could also mean hate to some people.

You know — it could be misinterpreted by some small group of overly sensitive types. Are you kidding?

In order to address the concerns of Jewish students on campus, the school held a meeting with the sixth-graders.

The meeting could have lasted about two minutes and offered the following explanation: The swastika is a symbol of Nazism. Nazis exterminated 6 million Jews in the last century and about 5 million others, including Soviet prisoners of war, disabled people, homosexuals, Jehovah’s Witnesses, etc. Unless you’re doing a history presentation on the Holocaust, don’t draw that symbol. If we catch you doodling swastikas, you’ll be suspended.

Instead, parents say “teachers spent nearly 12 of the 15 minutes on a PowerPoint presentation on how the swastika was still considered a sacred symbol — while only briefly mentioning how the Nazis had adopted it in the 1920s.” And they never mentioned the word Holocaust.

An irony of our age of microaggressions and trigger warnings is that anti-Semitism has become increasingly acceptable in schools. College campuses are overrun with movements to “boycott” and “divest” from Israel, motivated and accompanied by virulently anti-Semitic rhetoric.

At UC Davis, Muslims taunted Jewish students with chants of “Allahu akbar,” and swastikas were painted on a Jewish fraternity. At UCLA, fellow students accused a candidate for student judicial board of being too “active in the Jewish community” to “maintain an unbiased view.” Meanwhile, the mere presence of a building named after Woodrow Wilson, an American president who treated blacks as inferior, is too much for modern sensibilities.

The Post reports Tuesday that the school plans an assembly to apologize for the swastika incident, and is considering adjusting its curriculum as well. Fine, but it misses the educational atmosphere at the school that enabled this to happen in the first place.

Third-graders this year had to identify their race in a questionnaire and then, once a week, were put with others who looked like them to discuss the horrible things that were happening to them. One girl put her hands into another one’s hair. A boy asked his Asian friend where he’s really from. Another one dressed up in blackface to give a historical presentation on Jackie Robinson.

There is a distinction to be made between kids being curious about the way other kids look and kids who are drawing swastikas around campus and praising Hitler. But it’s not the distinction these adults are making.

In the case of the former, it’s to exaggerate the slight and make sure every curiosity is seen as racism. For the latter, it’s to downplay the offense because Jews are no longer seen as part of a class that needs protecting.

Grade schools, of course, shouldn’t be holding contests to find out which ethnic or racial group is the most oppressed. Slavery and the Holocaust both need to be understood as horrific examples of the evils of which human beings are capable.

But they should also understand that the United States offers oppressed groups the unprecedented opportunity to escape their pasts.

Unfortunately, in today’s educational institutions the real lessons are lost. Meanwhile, the only way to gain the moral high ground is to claim victimhood. Which means that someone else must be the oppressor. The Holocaust can’t matter to these educators because Jews, in their view, are now the bearers of white privilege.

Fieldston says it offers “excellence in progressive education,” but really it sounds more like the breeding ground for racist crackpots. If this is progress, parents should ask for their money back.

Naomi Schaefer Riley is a senior fellow at the Independent Women’s Forum.