Israel - Iran won’t be a “war”. It will be a quick erasure of muslims and take maybe 30 minutes from start to finish.
Horrific? Depends on who’s looking.
Sorry, I think it will be more like a couple hours. Iran does have many capabilities. But if Israel goes full ahead (without nukes), Israel will take the skys against Iran's aircraft. Once that happens, Iran is toast.
Remember modern Warfare 101: He who controls the skys, controls every thing.