Rabbi David Kalender leads an “Israel-focused” synagogue in Fairfax County. He believes that Israel is seriously threatened by Iran’s nuclear program and that “some bad things are coming down the pike.” He also knows the Jewish holiday of Yom Kippur brings perhaps his largest crowd of the year.

But Kalender’s sermon Wednesday to Congregation Olam Tikvah’s 600 families will be not about Israel and Iran but about Apple founder Steve Jobs and the importance of balancing ambition with humanity.

“We’ll address it in other ways, through a prayer for peace,” Kalender said of the rising tensions between Israel and Iran. The key, he said, is not letting the conversation wander into partisan American politics, particularly on the holiest day on the Jewish calendar. “I’m trying hard personally and for the congregation not to get lost in the potentially frightening existential questions. But we have to acknowledge them.”

Yom Kippur presents a test for American rabbis this year, who must guide Jews through perhaps the most personal and soul-searching day of the year in the midst of a brewing nuclear standoff in the Middle East and an American presidential election. Should they discuss Israel, and how? Should they risk setting off partisan bells with mentions of sanctions vs. war? Is Yom Kippur the day to make American Jews deal honestly with how close they feel — or don’t — to Israel?

From Tuesday sunset to Wednesday sunset, Jews are told to envision and pray about their own death in order to force a square look at themselves, their lives, and what they need to heal and improve to be nearer to God. They wear white and fast to intensify the day.

Yet even as Yom Kippur demands pursuit of the spiritual, the worldly is imposing itself this year.

Iranian President Mahmoud Ahmadinejad will address the U.N. General Assembly on Wednesday — a coincidence one local rabbi called “profoundly ugly” — and perhaps repeat the comments he made this week about “the occupying Zionists” who he says are dragging the United States into a possible war. Iranian leaders in the past have threatened to eliminate Israel, and Israel and the United States have said they won’t allow Iran to develop a nuclear bomb. It’s unclear whether that is happening, and Iran says it intends to simply develop a peaceful nuclear power program.

On Monday, several major organizations of Orthodox American Jews released what one leader called “an exceptional request” for congregations to let politics and prayer mingle.

The statement by the Rabbinical Council of America, which represents hundreds of Orthodox rabbis, and the Orthodox Union asked people to “pray for an end to the threat of a nuclear armed Iran.”

Yom Kippur prayers say God decides on this day who will live and who will die in the coming year and “which nations shall face war and which shall enjoy peace.” These words, the statement said, “prompt us to contemplate with anxiety the fate of the state of Israel and her people, of Jews throughout the world and, indeed, of civilization as a whole.”

Views on how or whether to discuss Israel and Iran vary widely among rabbis, including in the Washington area, where people’s lives are often saturated in politics and policy.

Joel Tessler, rabbi at the Orthodox synagogue Beth Sholom in Potomac, said he has been weaving mentions of Iran into his sermons over the past few weeks and would again during Yom Kippur. He believes that this will be the final Yom Kippur for hypothetical Iran talk and that there will be either a political or military “solution.”

Tessler’s actual sermon Wednesday will be about time. “Learning to appreciate and making every day count. But somewhere in there I’ll weave this idea that we live in, I think, precarious times.”

“In the end, our obligation is to say, put your fate in God’s hands and pray God deems it fit to protect the people of Israel and protect this country,” he said.

Others said Yom Kippur is a time to focus on changing yourself, not the outside world.

“I just feel it’s truly a political issue. And I know as much as anyone knows, which is very little,” said Rabbi Charles Feinberg of Adas Israel, the District’s largest Conservative synagogue.

Feinberg said Yom Kippur is primarily about personal relationships. He planned to speak Wednesday about ancient commentary on the holiday’s name: Yom Kippurim, the Day of Atonements. Some say the name could also be read as “A day like Purim,” a festive Jewish holiday when people wear masks. This holiday, the commentary says, is about taking off the masks we wear to others, but most important to ourselves.

Rabbi Bruce Aft at Adat Reyim in Springfield said that his congregation would discuss Israel and Iran tensions during adult education programs outside the holidays. Over Yom Kippur, he said, they would chant prayers for people hurt and killed as a result of terrorism, including in the recent attacks in Libya.

“We say a special prayer for healing, to ask God to give us courage to make our lives a blessing and grant us all complete healing,” he said. “We are one of those congregations where people want to get spiritually recharged. So many people work in government agencies, they want a break.”

But Rabbi Stuart Weinblatt, who leads the 625-member Congregation B’nai Tzedek in Potomac, said the possibility of millions of Jews being threatened is a Jewish issue and appropriate for discussion on the holiday, politics aside. On Wednesday, he said, he will speak about Iran.

“Last year, I said, ‘I want to give a nonpolitical sermon.’ And it was all about Israel. We need to speak about political issues without being political and contemporary issues without being partisan.”