My theory is Israel has been feeding fake, self-serving, "intelligence" about Iran, to the US for years.

There’s plenty of blame to assign to Israel for its warmongering, without inventing a “fake intelligence” conspiracy theory. The key intelligence was widely known and agreed to for many years. The Iranian nuclear project, how much they have and where, and the level of enrichment. Their ballistic missile and drone capabilities, the size of their military, their proxies - location, size, capabilities. All widely understood and assessed. No significant surprises there. The errors have not been in intelligence but in the consequent decisions. And Israel’s war mongering isn’t new. It fought tooth and nail against the JCPOA while it was being negotiated and after it was signed. All in the open. Not much to hide. The fact that Trump went along and ultimately decided to embark on a stupid war is all on him.