I think the feeling is that Israel isn’t going to take a gamble on that. They are not going to let Iran get to the point where their own military can no longer do the job (using conventional force) and they have to depend on someone else, friendly or not, for their own security.
I don’t know that they want our help militarily, I think they would like us to make it economically wise for the Chicoms to stay out of it. That said, I guess it does come down to how long the Israeli’s think they have until Iran can deliver a nuke.