So shooting down drones and missiles from one regional power is de-escalatory, while shooting down drones and missiles from a different regional power is massively escalatory. Makes perfect sense, thanks.
Yes, very different situations. If for no other reason than that in one situation every involved party had consented. Including Iran, tacitly.
The reason it was “de-escalatory”: It helped Iran prove what it sought to prove: no AD in the world will stop their missiles from getting through. For Israel it provided the face-saving “99.9%”.
Also, the Ukraine situation has no Jordan, Iraq, accessible ocean (ask the Turks about that) to operate from.
The other would almost certainly end up being called WW3, and would likely involve at least a limited nuclear exchange.