So is the idea that the US would start bombing Iran without a plan, goal, or any thought to the consequences, yet here we are...

There is a difference, basically the entire world hates the Iranian regime and wants them gone, USA bombing the Iranian regime wont get that much pushback from the world even if the war was started in an underhanded way.

It is entirely different if USA starts attacking NATO allies such as Denmark which isn't a threat or problem to anyone, that is not something anybody would expect and it would ruin American diplomacy completely.

Does US care about diplomacy anymore ?

Yeah, otherwise why would Trump only attack hated countries? He would have already started bombing Canada since its the closest.

2028 is very, very far away.

C'mon people, no NATO member is going to attack any NATO ally. Be real.

Unfortunately, that adjective applies to many things which the US has attempted, often "successfully", recently.

Lots of what Trump says is utterly ludicrous. But he does lots of what he says (though not everything), so the rest of the world is right to prepare.