Israel-haters are doing a fine job of eroding the supposedly bright line between “antizionism” and “antisemitism,” proving that there’s no difference between loathing Jews and opposing the only country dedicated to protecting them.

The latest demonstration came Wednesday at New York University during a huge graduation block party on the streets around Washington Square Park.

Some demented “activist” chose that moment of celebration to hoist a noxious banner resembling the Israeli flag but doctored with Nazi swastikas and the NYU logo.

And raised it atop the Steinhardt building, named for a prominent university donor also well-known for his interest in Jewish causes and his support for Israel.

This latest insult — equating the Jewish people with the very regime that erased 1,000 years of European Jewish life — came just days after a “protest” outside a Brooklyn synagogue morphed into a parade of hatred through a predominantly Jewish residential neighborhood.

A screaming mob with rags wrapped around their faces waved the flag of Hezbollah and shouted disgusting slogans demanding that “Zionists” vacate Brooklyn.

These folks keep insisting We’re not against Jews — just Zionists!

But they were besieging a Jewish synagogue and a Jewish neighborhood in Brooklyn, and calling local Jews “babykillers.”

Claiming any meaningful distinction between “Zionists” and “Jews” in these cases is the equivalent of demanding that Jews prove themselves to be innocent, presumably by denouncing Zionism.

To paraphrase Jean-Paul Sartre, antisemites enjoy accusing Jews of theft to make them empty their pockets to prove their honesty.

It’s a humiliation ritual.

Whoever raised the Hakenkreuz at NYU wasn’t making some humanitarian gesture about suffering Gazans.

It was a gesture of hate, meant to make Jewish grads and their families feel scared and ashamed, with no right to celebrate.

NYU must find the culprit or culprits and prosecute them openly.

If they’re students or graduates, expel them or revoke their diplomas.

Normalizing bigotry leads straight to scapegoating and violence; civilized people must censure the haters.

Stop the infection before it spreads any more.