Updated, Saturday, 3:54 p.m. | Sheldon Adelson, a leading donor to conservative politicians who share his staunch support for Israel, said on Tuesday night that the United States should begin negotiations with Iran over its nuclear program by launching a nuclear strike on the Iranian desert.

The billionaire casino magnate, who donated nearly $100 million to Republicans last year, prefaced his remarks during a forum at Yeshiva University in New York with the observation, “If you really want peace, it’s very simple to send a message to your opposition.”

Video of the event posted online by Philip Weiss, a blogger who comments on Israel “from a progressive Jewish perspective,” showed that Mr. Adelson was asked about President Obama’s recent diplomatic outreach to Iran. A shorter YouTube clip recorded from a better angle by the BBC Persian journalist Bahman Kalbasi captured his response:

What are we going to negotiate about? What I would say is, “Listen, you see that desert out there, I want to show you something.” You pick up your cellphone … and you call somewhere in Nebraska and you say, ‘O.K., let it go.’ So there’s an atomic weapon goes over, ballistic missiles, in the middle of the desert, that doesn’t hurt a soul. Maybe a couple of rattlesnakes, and scorpions, or whatever. Then you say: “See! The next one is in the middle of Tehran. So, we mean business. You want to be wiped out? Go ahead and take a tough position and continue with your nuclear development. You want to be peaceful? You want to be peaceful? Just reverse it all and we will guarantee you that you can have a nuclear power plant for electricity purposes, for energy purposes.” So.

Such a show of force, Mr. Adelson added, is “the only thing they understand.”

Mr. Kalbasi, who reported the comments in a BBC Persian broadcast, also noted that the conservative columnist Bret Stephens said moments later that he agreed with “98 percent” of what Mr. Adelson said.

Bret Stephens says he agrees with 98% of Sheldon Adelson’s statement on #Iran. — Bahman Kalbasi (@BahmanKalbasi) 23 Oct 13

As my colleague Jodi Rudoren reported in May, Mr. Adelson, 80, is also an influential figure in Israel. Married to an Israeli, he owns a Tel Aviv newspaper that frequently amplifies warnings from Prime Minister Benjamin Netanyahu that a nuclear-armed Iran would pose an existential threat to the Jewish state.

After a meeting with Secretary of State John Kerry on Wednesday, Mr. Netanyahu said that any deal that allowed Iran to retain a path to a nuclear weapon was unacceptable to Israel.

Supporters of talks with Iran, including the Iranian-American journalists Arash Karami and Hooman Majd, joked about Mr. Adelson’s conception of a vast stretch of desert in Iran populated only by rattlesnakes, like those found in the American Southwest.

@hmajd didn’t realize there was rattlesnakes in Tehran. Adelson has really done his homework on this theory. — Arash Karami (@thekarami) 23 Oct 13

@thekarami He was thinking Nevada. But the Iranians would never retaliate by nuking Vegas–too many Iranian expats there every weekend. — Hooman Majd (@hmajd) 23 Oct 13

That Mr. Adelson’s comments were made at a forum on “Iran, Assimilation and the Threat to Israel and Jewish Survival” reminded the graphic artist Eli Valley of a political cartoon he published last year in the Jewish-American daily The Forward, which poked mordant fun at the extremism sometimes found at such events.