Look up Operation Northwood and you'll see what the US government is capable of and that was 60 years ago. This isn't some crazy theory, it's declassified from the US Govenrment.

https://en.wikipedia.org/wiki/Operation_Northwoods

Do I think Iran was designed as a distraction? Honestly I really don't know. Maybe it was convenient and accomplished multiple goals for the administration.

I think anyone dismissing the theory outright and mocking anyone who thinks it might be a possibility is being extremely cocksure though.