As the old Gershwin brothers’ tune notes, differences over even so trivial a matter as the pronunciation of “tomato” can lead to a desire to “call the whole thing off.”

Jews following the odious history of the United Nations’ relationship to Israel post-1948 are concerned with far more critical differences — but when it comes to the U.N., many Jews would love to call the whole thing off.

That, says Sybil Kessler, would be a grave mistake.

“Some say we should eliminate the U.N. altogether. My view is, you can’t divorce the world,” said Kessler, the director of United Nations affairs for B’nai B’rith International.

“Sometimes the U.N. doesn’t solve problems but makes them worse when it becomes an echo chamber for the world’s worst voices. But that’s why we need to be there to stop that from happening. And don’t think that if we took the U.N. away this wouldn’t be happening anyway.”

The New York-based advocate will be in the Bay Area next week for a series of speeches.

When she isn’t objecting to the U.N.’s condemn-Israel-a-thon, Kessler is pushing for other issues near and dear to the Jewish community: religious freedom, human rights and combating global anti-Semitism and racism.

“We want to see human rights promoted — but not by haranguing one country and escalating conflict,” she said.

While the U.N. is not always a great place to be for an Israel supporter, Kessler has seen progress. For the last three years, the U.N. has held an annual Holocaust memorial — after markedly not doing so for more than 60 years.

And though the delegates of some nations seem be wondering “how can I stick it to Israel today?” when they wake up, Kessler has been successfully lobbying more and more nations to not automatically vote anti-Israel.

“It’s not easy. But there doesn’t seem to be a better way. And just because it’s a challenge doesn’t mean it’s not worthwhile,” Kessler said of her work.

“Nobody said it was easy being Jewish.”

Sybil Kessler, director of United Nations affairs for B’nai B’rith International, will make four speeches in the Bay Area. All are free unless noted:

• Tuesday, March 25, 7:30 p.m., Congregation Beth David, 19700 Prospect Road, Saratoga. Tickets: $5.

• Wednesday, March 26, 1:30 p.m., Congregation B’nai Shalom, 74 Eckley Lane, Walnut Creek.

• Wednesday, March 26, 7 p.m., Congregation Beth Israel-Judea, 625 Brotherhood Way, S.F.

• Thursday, March 27, 7:30 p.m., Peninsula Jewish Community Center, 800 Foster City Blvd., Foster City.

RSVP to Lesley Welwart by email at [email protected] or call (707) 980-7565.