Fatal mistake that the US and Israel have made is Iran et al are not set up as a state. Thats why when you take out the "head" of an organisation it simply carries on. - Iran has been allowed decades to set itself and its proxy's up and to harass the region. But as I say its not a state its more a terrorist network with Iran - Hezbollah - Hamas - Houthi's - ISIS and beyond part of but not members of the State of Iran.
Because of this misunderstanding they have failed in preparation and tactics because they are fighting an enemy that will accept civilian losses to fight on - they planned an attack on Iran not a deadly game of whack-a-mole. You hit one location and retaliation comes from a different country. The US thought striking Iran would cause an uprising but Iran is like the DDR - full of soldiers and secret services and not a place where people are, as yet, not prepared to do.
Israel in the meantime has its own goals however they are taking a panning on the battlefield and at home in Tel Aviv because they banked on the same things that the US did and never considered that they would get attacked from multiple locations by multiple groups in a co-ordinated way - nor did they realise that the current administration was so tactically inept.