According to all intelligence reports by the UN's International Atomic Energy Agency and the US's CIA/NSA, Iran is not trying to develop nukes and has fully abandoned their nuclear program. Anyone saying elsewise is simply saber rattling.
What the are doing is developing a civilian nuclear industry. Such an industry---like any other industry---has the potential for making military development easier in the future, but that is not its primary purpose.
Considering the current geopolitical climate, you have to be extremely naive to believe that Iran's long term goal is not developing nuclear weapons. A "peaceful" civilian nuclear industry is only the first step.
I don't think Iran's primary motivation for wanting nukes is US nukes. It might be, in part Israeli nukes, but I bet it's primarily conventional war with the US and/or Israel. Iran likely believes that having nuclear weapons of its own will discourage conventional attack.
That line of thinking isn't unreasonable. As far as I know, there has never been open conventional warfare between two nuclear-armed states - just minor skirmishes.
What the are doing is developing a civilian nuclear industry. Such an industry---like any other industry---has the potential for making military development easier in the future, but that is not its primary purpose.