During the 2012 Republican primary campaign, the panelists on the ABC Sunday morning talk show This Week were asked to comment on a remark by Donald Trump. George Will, a generally reserved, dignified and unexcitable conservative, simply exploded. Trump, he said, was a “bloviating idiot,” and in Will’s opinion, unworthy of any serious consideration.

It is now official. With his recent proposal that America should drop an atomic bomb in the Iranian desert and threaten to drop one on Tehran, Sheldon Adelson has become the Donald Trump of the Jewish world.

While some might dismiss the comparison, it seems apt in every way. After all, both are wealthy. Both despise President Barack Obama. Both have a penchant for saying idiotic things. And, yes, both have some very serious accomplishments to their name.

I will leave it to others to review Mr. Trump’s successes and acts of kindness, but Sheldon Adelson’s good works are known to all in the Jewish community. He has donated to a range of charities with extraordinary generosity, and he has been the largest donor to Birthright—the single most impressive and impactful Israel program for Diaspora Jewish youth. Absent his largesse, Birthright as we know it might not exist. Such a record buys Mr. Adelson a measure of tolerance and patience that would not be accorded to others.

But only up to a point, and that point has now been reached. His Iran comments were obtuse, insensitive, and morally bankrupt; and, just by the way, they were also harmful to Israel’s interests and destructive of American Jewish efforts to craft a persuasive position on the Iran issue.

The situation now is that America and her European allies are committed to exploring diplomatic options with Iran. At the same time, they take pride in the sanctions they have imposed and are desperate to prevent the Ayatollahs from acquiring nuclear weapons. What is required here is a serious campaign of education, in America and abroad, making clear the dangers of delay and making the case for retaining and even increasing sanctions. When a politically prominent American Jew with close ties to Israel’s prime minister and problematic relations with the American president enters the fray, spouting rhetoric that is both jingoistic and absurd, American Jewish leaders can only groan in dismay. This is not how the battle will be won. This is not how the public will be brought to their side.

The larger point is that even in the very special case of Mr. Adelson, deference to wealth has its limits. No one is naïve here; the Jewish community, especially now, depends on people of means to support Jewish institutions and Jewish learning. It is to be hoped that Adelson will continue to give, and he, of course, has every right to say whatever he pleases. But outrageous remarks need to be branded as such. And adulation and honor should not be extended to those who think that the threat to “wipe out” Iran by dropping a bomb on Teheran is somehow consistent with American or Jewish values and interests. And perhaps the time has come for important leaders of our community to decline invitations to appear at Mr. Adelson’s side.

There will always be sycophants, explainers, and excusers. Rabbi Shmuley Boteach, in a particularly disheartening example of how this is done, wrote an article in the Huffington Post in which he explained, apparently with a straight face, that “Sheldon’s glib comments” were perhaps a bit hyperbolic but were intended to goad his liberal critics into attacking him so that their double standards would be revealed for all to see.

Sorry, Rabbi Boteach. It doesn’t work. What is needed here from Mr. Adelson is a thoughtful clarification and apology. The Iran problem is far too serious to be handled with bluster, blather, and idiocy.

Rabbi Eric H. Yoffie, a writer, lecturer and teacher, served as president of the Union for Reform Judaism from 1996 to 2012 and lives in the United States.