The USA Military strategists are/were quite aware that Iran is not an easy target.
They knew already that Iran might not belly up just because their leadership gets killed. And they knew very well how Iran is fighting (in the mountains) and that they will close the strait of hormuz
Trump overruled it. He thought it was as easy as venezuela and he might have assumed that the civil unrest helps.
That's speculation. We were going to attack Iran regardless. My point was, the attack you are talking about was done _by_ Israel and was not part of the plan.
Isreals only power to doing so, was knowing USA was behind it.