Or it's a rope-a-dope. Every time Iran uses a new missile, the US gains intelligence. Every time Iran is forced to defend against a particular attack from Israel, the US gains intelligence. Every time Iran communicates with another group, receives or delivers materiel, or changes the configuration of their fortifications, the US gains intelligence.

So Israel may be getting sacrificed not because the US wants to hurt Israel but because Iran must have a target for the US to gain intelligence on Iranian capabilities.