I think Iran will eventually retaliate again to try to save face so the great leader can sell to their population another great intervention, and that will probably be it.
Both of them, Iran and Israel have proclaimed that they're victors on this war and that's why if they will retaliate and do something nasty again. I think that the US won't have a second thought to stop them.
Honestly, I have never believed that there would be a World War 3 just because of the conflict between these two Middle Eastern countries.
It's the opposite for me.
With the Russia-Ukraine and then Iran-Israel war, this really could startled a world war 3 if wasn't stopped too early. Both have great allies and superpowers that can wipe out such lands and make everyone part of the recoil of their missiles.