There are only two ways to regime change, a coup or ground invasion, the coup path got burned when they attacked unprovoked and without even bothering with a casus beli, they're not even bothering with talks of democracy and just fronted their old monarch dictator.
Ground invasion require staging troops and even Trump knows it'll be a disaster they'll probably lose. Of course that doesnt mean they wont do it, American politicians are very opem about putting Israel first, they'd see America burned to the ground if Israel demands it.
IMO Trump personally want to look tough and already said too much to back down, but he dont actually want a ground war. Because of this he's probably been sold some kind of win with only a bombing campaign. It obviously wont be enough and they just went through this with Yemen, so those who sold it are really counting on Iran's retaliation on US assets to then sell a ground invasion. Trump himself might not be able to see the second step, if he did he'll try to delay as much as possible while looking for a face saving way out.
I dont think we can assume they know what they're doing, infact judging from the trade war to tech war to bio war its more than likely they dont actually have a plan. At end of the day Israel cant survive a protracted war with Iran so US has to do something, but that something is probably winging it rather than anything cohesive
