Why does russia back iran?

hi there it's all in the money Iran sells Russia nuclear Iran has the most weapon any men can want. the excuse is simply it's for making energy . now who in their right mind believes that. to my understanding they all hate united states and by getting together to see and make more nuclear it's a way to get rid of America. What is United states doing taking it easy to that nuclear will not be send our way one wrong move towards these countries and destruction is on the way. but that is my way of thinking towards this countries and their dirty secret.