Israel is an existential threat to Iran because of their control over the US. The Sunni Arabs States are a manageable national security concern. The US is not. Besides, Israel and the US are not interested in a friendly Iran. What they want is Middle Eastern hegemony and Iran existences cannot be tolerated as an independent state.
Looks like that the main concern of Iran has always been the expansionist nature of Israel and in especially in Lebanon who has a big population of Shia. Iran is basically the first domino they probably want to fall, well the first was Saddam, but Iran is the biggest, that will allow to take Lebanon literally with impunity then expand to Iraq.
But if Iran has been compromised from the inside I cannot even imagine the time bomb in Saudi Arabia, the Gulf States and Turkey. They probably infiltrated every single aspect in these societies, sleeper cells everywhere in the Middle East and the Muslims world. If they managed to destroy Iran they will continue to fragment and destroy from inside and outside the rest of the Arab states until they fragment into powerless token regimes with punny no defined territory and I don't think this, let admit it, death cult, care if they kill millions in the process or start WW3. They want to be the only power in the Middle East, not even Saudi Arabia. Is damn obvious.
I'm someone that not believe to much in conspiracy theories but this is creepy stuff. Right now you have now while his country is being bombed out of oblivion by Iran Netanyahu is rushing to bomb the hell out Lebanon and invading them.