So based on the "past", Iran should attack the U.S ASAP because the past has shown the U.S has made it possible for tens of thousands of Iranians to die. Almost all of them civilians.

So with those assumptions, the U.S must be behind the terrorist attacks inside Iran. Yes, there are terrorist attacks inside Iran and since the U.S is next door and has attacked Iran in the past indirectly, they must be behind them.