In 1962, the New York Board of Rabbis tried to block a telecast of The New York Shakespeare Festival’s Merchant of Venice. A delegation met with Joseph Papp, the company’s famed director, to convey their “deep concern lest a revival of the anti-Semitic stereotype of Shylock on the television screen do great harm to intergroup amity and understanding in our city,” according a JTA dispatch at the time.

“Mr. Papp reacted negatively,” JTA reported, and the play, starring George C. Scott as Shylock, aired locally on CBS. How much harm was done to “intergroup amity and understanding” has gone unreported.

Fifty-two years later almost to the day, the Anti-Defamation League announced that the Metropolitan Opera had agreed to cancel its planned HD simulcasts of The Death of Klinghoffer, John Adams’s 1991 opera depicting the notorious terrorist attack on the Achille Lauro. (A Met staging of the opera will go on as planned.) In welcoming the Met’s decision, the ADL acknowledged that while “the opera itself is not anti-Semitic, there is a concern the opera could be used in foreign countries as a means to stir up anti-Israel sentiments or as a vehicle to promote anti-Semitism.”

In an age of viral videos inspiring violent mobs in Pakistan and Libya, it is hard to dismiss any work of political art as “just an opera” or “just a movie.” At the same time, it is hard to imagine that the kinds of audiences drawn to Adams’s spiky, challenging works would rush out of a four-hour opera baying for Jewish blood.

So if the opera is not anti-Semitic, what’s the problem? The ADL also worries that the “opera’s biased portrayal of events” could “legitimize terrorism.” I’m not sure what they mean by “biased.” Jewish groups lose me whenever they try to quash anything that looks like sympathy for the Palestinians. Legitimate if provocative protests by pro-Palestinian groups on campuses are treated as hate crimes. Intellectuals who express their qualms about the settlements are accused of condoning terrorism. Jewish theater companies that present works portraying Israel as anything but saintly are threatened with boycotts. Under cover of “anti-anti-Semitism,” we spend too much time trying to silence those who disagree with us. If that’s the ADL’s intention in protesting Klinghoffer, that would be a shame.

But I don’t think that is what is going on here. Defenders of the opera say it inflames passions because “the bad people in it are not entirely bad, and the good people are not entirely good,” as its librettist, Alice Goodman, once said. I’d say the opera inflames passions not because it is even-handed (although many viewers are bound to hate that), but precisely because it treats one of the ugliest and most despicable acts of terrorism as a basis for something like entertainment.

Jews and Israelis who support a two-state solution — probably a majority — have accepted that a just resolution of the conflict includes a Palestinian state. A solid plurality would even acknowledge that injustices were inflicted on the Palestinians when Israel was founded and continue today in the territories. But no one can forget the long string of barbaric attacks on innocent Israelis — the murders of kindergarten children, bombings of Passover seders, the deaths of college students in cafeterias and on buses, and now the kidnapping and presumed terrorizing of three teenage yeshiva students. Most liberals I know are disgusted by the self-defeating violence of the Palestinians — and by those who seek to explain or justify it as the understandable acts of a  “desperate people.” As even Mahmoud Abbas acknowledged recently, it’s the terrorists who have stained and undermined the Palestinian cause.

Any sympathy the opera tries to bestow on the Palestinians (“My father’s house was razed/ in 1948 when the Israelis passed/ Over our street,” sings a “Chorus of Exiled Palestinians”) is undermined by the sheer inhumanity of those who in real life shot an elderly man in a wheelchair and threw his body overboard. You want to talk about legitimate grievances on both sides? Fine. Just don’t do it over the empty wheelchair of man murdered for the crime of being Jewish.

Adams had every right to make a work of art about one of the most important conflicts of our time. But he made a reckless decision in using the murder of Leon Klinghoffer as his framing device. It’s an insult to Jews, Americans, and, in truth, to the Palestinians themselves. “This opera does not romanticize terror,” the music scholar Robert Fink assures us. The critic John von Rhein calls it “a nuanced meditation on Middle East violence and religious intolerance.” But perhaps what the ADL is saying is that nuance and terror don’t belong together — that nuance, the hallmark of good art, ends up softening the effects of terror, the most despicable of “political” acts. Art tends to stylize even ugly things, in what my English professors would call “aestheticization.”

Does Klinghoffer condone terrorism? Hardly. But it does make the horror of what happened to Leon Klinghoffer less real. As Klinghoffer’s children wrote last week in The New York Times, “Our 69-year-old father was singled out and killed by Palestinian terrorists on his wedding anniversary cruise in 1985 solely because he was Jewish.”

The opera turns this stark fact into a theatrical conceit, a symbol, a device, when so many would consider the murder that inspired it unspeakable, and certainly unsingable.