Spent all that money playing around with F-5 clones instead of buying some decent interceptors in the 90’s or building one with a massive national focus like Bavar-373 project
Jet's won't make much of too much of a difference if the US decides to go to war with Iran. Even if Iran had bought the best Russian / Chinese jets last year, in the end export versions can't compare with the weapons that a superpower like the US possesses. Iran's best bet is their defensive weapons, missiles, ballistic, cruise, supersonic anti ship missiles, etc Realistically though in a full scale war Iran would suffer more than the US. Iran can't really win a conventional war against the US face to face
The US presidential re-election is nearing and I highly doubt Trump would start a war with Iran during that time. Most likely Trump is bluffing about attacking Iran directly, but who knows, he doesn't seem to have a consistent strategy or even principles to stick to.
Iran's best bet right now is to bog America down in a terrible quagmire in the middle east. Iran could do this by giving proxy forces advanced weapons, even arming the Taliban with missiles, rockets, ATGM's, manpads, sniper rifles with armor piercing rounds.
After 20 yrs the taliban with a bunch of rusty weapons and sandals currently control 25% to 1/3rd of Afghanistan. Iran could even send in some tactical sniper units dressed in Ghillie suits. The Americans would get wrecked and before long would have to send in re-enforcements.
Iran can do the same thing in Iraq. I'm sure Iran has tunnels going into Iraq. My guess is that they're currently at a stage where they're planning things out and moving, transporting weapons into place
Another option would be to do what the Chinese do and pump drugs into the USA. Think about it, the US is sanctioning Iran and despite this Iran is responsible for 70% of the worlds Opium seizures and Iran's population suffers extensively from the illegal drug trade in Afghanistan. Instead of burning the seized Opium, Heroine, etc Iran could make a massive profit, re-direct some of these drugs to the EU and then US. That would be very immoral but desperate times call for desperate measures.
I'm not advocating any of this but I can guarantee that these are options which the Iranian leadership is considering.