Iran had several opportunities in the last 10-15 years to acquire JF-17 or J-10 or even the Russian Sukhois. But it decided to forgo advanced fighter jet acquisition in favour of missile programme, and left the Iranian Air Force to make do with reverse engineered F-5s. Missiles can attack the enemy but cannot defend the home country like the fighters jets do. An up to date air force would have been able to impede the Israeli air strikes. Its a shame considering that the Iranian Air Force used to be the best equipped air force in the Middle East once and even out performed the Iraqis during Iran-Iraq war. Their reward was to become obsolete to the point of non-existence.