It would be very easy to frame Iran as the culprit. And, you wouldn't need a tinfoil hat, either.
Do you think the Terrorists are trying to get Iran in trouble?
Do you think the US has found warheads somewhere and is using them to get Iran in trouble? I think country of origin is pretty easy to determine for such things.
Usually, when I don't know who else to blame, I blame the French. But when warheads are coming over the border from Iran, I tend to turn my attention away from France.
So, who do you think is doing the framing?