Rabbi David Wolpe ("America's most influencial rabbi" according to Newsweek) is known to many, no need to go through his many accomplishments here. 

However, in support of Rabbi Wolpe's call to action, we are sharing the mp3 file of the sermon he gave on Rosh Ha Shana this year - a sermon that Rabbi Wolpe describes as so important that if he only had one sermon left to give, this would be it. 

"We stand on a precipice."  Please listen.

An abridged version of the sermon, entitled "The Most Important Question in the World Today," appears at TIME.com. 

You can read it there, where the Time magazine version ends at this paragraph (his sermon continues in the full version):

With the exception of Hiroshima and Nagasaki, humanity has managed to restrain itself from deploying this most awful of weapons, the one that can indeed destroy worlds. We stand before an iron law of history: you cannot unmake what has been made. Once Iran has a nuclear bomb, the world will never look the same. Not only Israelis, but the West will never sleep easily in its bed.

Stopping Iran will not feed your family, get you a job or open a factory. It will not elevate the level of public discourse or bring manufacturing back from China. It will merely ensure that the free world, beginning with Israel but not ending there, will not live under the shadow of annihilation.

To our presidential candidates: show me you have a way to do that, and you’ve got my vote.