After a bombing campaign, most of the people tend to hate whoever bombed them.
On the other hand, until a couple of years ago, Iranians and Israeli never directly exchanged even a bullet between them and yet Iran was dedicated to the destruction of Israel, so YMMV.
Something the current US regime might have forgotten.
Israel has been killing iranians for quite some time. Here are some notable examples from the last twenty years or so:
https://en.wikipedia.org/wiki/Assassinations_of_Iranian_nucl...
The rebuild phase where allies put a lot of effort and money into rebuilding Germany did a lot to ensure good result there. And you still see fascists being popular in Germany, especially in former easter block. It is just that everyone else is still traumatized by the past, school system make sure everyone knows past and nazi propagation is literally illegal.
You know what engenders nationalism? Attack on your way of life and the murder of someone you know by said attack.
If the enemy does the same kind of mindless killing to the civilians, then I would have different ideas.
You mean like bombing a school and killing about 150 schoolgirls?
The USA had a lot of local support and goodwill in Afghanistan, and turned it into support for the Taliban, because they kept killing civilians in their attempts to beat the Taliban with bombs, because they wanted to limit the unpopular ground troop deloyments. The chance that the same will happen in Iran is precisely 100%
You can't say for sure that you wouldn't wilfully join up if you were in that kind of information environment.
It doesn't mean that people like America- or Israel.
Every country has it's own elite who have their agenda independent from whatever the White House wants.