That's not how a nuclear umbrella works. Nukes are there to counter other nukes. In short, they're largely political weapons.

Nope. Nukes also serve the purpose of deterring conventional attacks. Israel didn't go out and get a nuke because they were concerned that one of the world's other nuclear powers might attack them with nuclear weapons - Israel's nuclear threat is also there to make sure that no other country (specifically Iran) can try to wipe Israel off the map with conventional forces without having a nuclear weapon dropped on their capital in the dying throes of the country.

I said "tune him up" which means "kick his a$$ hard enough that he learns his lesson or finds other targets to prey on". Either outcome is acceptable.

Except what if he doesn't? What if he instead goes out and gets a knife or a gun and decides to come back and kick your ass? Or perhaps uses the knife or gun to threaten to hurt one of your kids? Something he might not have done when he was just "neighborhood bully," but is now on the table because you've escalated to actual direct physical conflict?

You've ratcheted up the problem, and you very well might have made it much worse for yourself. Which is why "getting into a fistfight" is not always the best way to deal with a neighborhood bully. That doesn't mean the neighborhood bully isn't a problem, nor that you don't need to do something about it. But if the neighborhood bully doesn't respond by doing what you want, or slinking away, then you very well may have made the situation worse.

And you all have made this point 1000 times already. That's nice; it just also happens to be largely irrelevant because we are where we are at this point in time.

It's not the least bit irrelevant - because what we do going forward depends entirely on whether military action against Iran can accomplish any strategic goals. If blowing up stuff in Iran is not going to materially advance any security goal of the U.S. or delay their nuclear ambitions in any significant way, that's an obvious reason why we shouldn't have started the war in the first place - but it's also a hugely significant factor that we need to consider in deciding what we should do now. It's also a hugely significant factor in negotiations with Iran over how the war ends, because if what we've done hasn't materially weakened Iran's long-term threat profile in the region then we're going to have a much smaller set of possibly obtainable goals in a negotiation than if we have materially weakened their long-term threat profile.