But the fact is that Iran has no air force or any other serious military hardware to defend itself. Because simply they wouldn't sell them to Iran. Most Persian gulf countries have military budget per capita orders of magnitude larger than Iran. In addition they have the might of US military behind them. Missiles are the only reason that Iran is not like Iraq or Libya right now. Iran has been on the hit list of Neocons since long time (you can refer to General Wesley Clark)
Iran experienced a very bloody war with Iraq during 80s where everybody was supporting Saddam Hussein from Soviets to the US and persian gulf monarchies. I know personally people that where harmed by Saddam chemical weapons but international community remained silent for too long. I remember seeing Saddam's missile on the Tehran skies but we had no means of stopping them or retaliating because again nobody cared.
About annihilating another state: How can Iran annihilate a state which has 200 nuclear warheads? It might be other way around.