You're both right by the way.

Israel can continue with or without America's help.

You said it yourself.

America is the only reason Iran and other countries have not yet attacked Israel...

Iran is technologically and militarily inferior to Israel. An open war between Israel and Iran ends inevitably with the collapse of Iran as we know it. They only people in Iran who don't know that to be true beyond any doubt are insane religious nutters who aren't being objective. That's why Iran's direct, retaliatory responses have been so tepid and ineffective; first they shot down their own passenger airliner, then they spent billions on ballistic missiles and only killed two people, and one was Palestinian. Iran is fragile.

Their like Mitch KcConnel or Liz Cheney, Mike Pence, they spent so much time and effort whipping up even crazier hardliners in order to stay in power (including Hamas, Houthis, and Hezzbollah) that now Iran risks being over taken by actual hardliners at the first chance, who might do something stupid like turn fissile material into a weapon or launch a ground invasion at Israel.

The general United States response in either of these scenarios is not much of a secret. You can read all about it if you like to read think tank material. The plan has two parts: Iran will not build a nuclear weapon no matter the cost, and an Iranian invasion force mobilizing on Israel will be met and utterly crushed by the 1,600,000 ground troops the Pentagon plans to send in this scenario. Iran knows all this.

That's why their direct retaliation has been so tepid, so incompetent and ineffective. First they got jumpy and shot down their own civilian airliner, then they spent billions on ballistic missiles and only killed two people, and one was Palestinian!

If the moderates in Israel start to think they might have a chance, nothing is left stopping Iran from building a nuclear weapon or invading Israel. In either case, remember, Israel is still a superior military force and will turn Tehran into a sheet of glass before one Iranian boot reaches Jerusalem.

Only obvious know nothings have hot takes on this that don't account for these realities.^^

In either path leading to the collapse of Iran, millions of innocent people will die and The world will be wishing we were back to the days it took a year to see 50,000 dead because then it will be likely be 50,000 every day. Going to make Netanyahu look like Ghandi.

The Iran Nuclear Deal was the world's last best chance at peaceful intervention. The only thing America can do now is make promises to Iran that we hope we don't have to keep and unfortunately, the Likud party in Israel has found a way to exploit that fact. Luckily, Israel is the only democracy in the Middle East, so something can be done about it.