If there was any outside visible thread of reasoning for this war it was "Iran seems like it could have regime change" and I haven't heard anything saying they're more likely to have a different form of government.
I doubt the revolutionaries sympathizers within Iran liked their children being murdered or infrastructure getting destroyed. All the US has done is a repeat of the same thing they've done for half a century: start a war and immediately get more enemies within the middle east. Perhaps the only change is now the US's allies are distancing themselves faster and further than ever before.
There was a lot more - since mid last summer the US and Iran have been talking. There was some progress on nuclear issues. However Iran refused to discuss their ballistic missile program or funding for the likes of Hezbollah. Just based on that alone it is no surprise that the US got fed up. However you have to pay a little more attention to see that even though it is public.
Sometimes you want someone to do something, but you don't have authority to order them around, and you are bad at persuasion and dealmaking, so you don't get what you want.
If you're not ok with walking away at that point, maybe put a better offer on the table?
I fail to see a better offer. Support for those trying to kill jews is not something I can accept. I don't like any option for dealing with it, but walking away is still evil.
I can't speak for you, but for me, as a jew, killing innocent people just to get what you want is bad, even if they aren't jewish. Support for genocidal wars of conquest (like russia's and israel's) isn't something I can accept.
Additionally: supporting the killing of innocents, war crimes, genocide, etc, just because the perpetrators are jewish, is eviler still. Israel's actions make all jews (like myself) look bad, and puts us at risk around the world.
Maybe try diplomacy instead? And no, diplomacy doesn't mean "take our offer with no changes or we will kill you all". It means recognizing that israel isn't better than other countries, it means treating others as equals, it means you don't get to boss around co-equal countries, and it means giving first if you want to receive.
I doubt the revolutionaries sympathizers within Iran liked their children being murdered or infrastructure getting destroyed. All the US has done is a repeat of the same thing they've done for half a century: start a war and immediately get more enemies within the middle east. Perhaps the only change is now the US's allies are distancing themselves faster and further than ever before.