October 15, 2012:
Why have Iranian anti-aircraft missiles and guns been firing on Iranian aircraft over the last five years? In several known cases Iranian jets were sent aloft to intercept what turned out to be Iranian airliners. It's all about the unanticipated impact of paranoia.
For over five years now Israel and the United States, and much of the media everywhere, have been making noise about attacking Iranian nuclear facilities. All these threats always seemed to have little impact on Iran. Some Iranian officials and military commanders made defiant statements in response, but most everyone understood that such an attack would only help the corrupt and unpopular Iranian government, by forcing the population to rally behind their despised leaders to defend the motherland.
But all this talk of an attack got through to many Iranians in the armed forces and, despite commanders being told that an attack was unlikely, no one wanted to be accused of letting the American or Israeli jets slip by them. To make matters worse, the Iranian military communications system is unreliable, so it's not easy to call someone to get confirmation of airborne intruders. To make matters worse, the training for the anti-aircraft troops is poor and there's always some trepidation when you let these guys near live ammunition. While there have only been a few incidents of friendly fire that Western intelligence have hard evidence on, it's believed that there were many more undetected incidents and that at least one of the many Iranian aircraft "accidents" in the last five years was actually someone getting shot down by a nervous anti-aircraft missile unit. Chatter among Iranian pilots indicates that there are certainly plenty of rumors about such accidents.