Iran Builds A New Jet Fighter

Iran Saeqeh (Thunderbolt) Fighter Jet

I do not understand Iran. (Yes, yes, I know I am not alone.) All I hear is how the crazy Iranians are lying about trying to make an atomic bomb. Why are they even messing with nuclear fission? Aren't they sitting on top one of the biggest pools of crude oil in the world? Pollution in Tehran is very bad. Rumor has it that it is that way because of the poor quality of gasoline they get from their own refineries. They are using their own gas because they can't import gas because of the sanctions. Yet here they are spending zillions on nuclear power. Why not spend two dollars and upgrade the refineries?
    As California Bob says, when things don't make any sense, it's a good bet that somebody's lying. So here's my theory: somebody in Iran has been cut out of the oil money, so he's promoting this nuclear nonsense so he gets a big budget to spend on it, and when he buys stuff from the West he earns a bunch of brownie points and some big fat kickbacks. Not sure which would be more valuable.
    As for this jet fighter, they are probably not building their own jet engines. As near as I can tell making a jet engine is a bit of a trick. Might even be a state secret. I don't think anyone really knows how they are made.