This spring, 30 ninth graders from a progressive private school near Greenwich Village went on a field trip.

There was nothing unusual about venturing out into New York City to boost their classroom studies. At the school, Little Red School House and Elisabeth Irwin High School, this sort of experiential learning was so routine that few parents were even notified of the destination: The People’s Forum in Midtown Manhattan, a hub for gatherings of left-wing activists. Its executive director has called for the destruction of Israel.

Afterward, parents were flabbergasted to learn where the students were taken, and what they were told.

During their visit, a People’s Forum employee gave the students a 90-minute lecture on the perils of America’s support for Israel and Ukraine. The students were “a captive audience who were subjected to anti-Israel and anti-American propaganda,” according to a grievance report filed by a parent and shared with school leadership. A handful of Jewish students walked out during the presentation, upset.

Later, the head of school, Phil Kassen, sent a message to parents acknowledging that he had been aware of the plan and taking responsibility for what he said was an error in judgment. “I could have stopped this trip,” he wrote. “I didn’t.” It was not his first apology this school year.

In the eight months since Hamas attacked Israel and Israel retaliated with a military campaign in Gaza, private schools across New York have been disrupted by strife over how to manage education about the war, political expression by faculty and students, and accusations of antisemitism and Islamophobia.