Fear of Israel had Iran scrambling to prevent
Fear of Israel had Iran scrambling to preventReuters

While an Israeli threat of an attack against Iran is speculated daily in the international media, classified Pentagon intelligence papers reveal that it was actually in 2008 that Iran was so fearful of an Israeli attack they mistakingly fired at their own airliners. 

The New York Times reported that between 2007 and 2008 tensions were so high in Tehran and the threat of an Israeli airstrike on its nuclear facilities was so strong that the Iranian military mistakingly tried to shoot down civilian airliners and in one case even its own military aircraft. 

“Iranian air defense units have taken inappropriate actions dozens of times, including firing antiaircraft artillery and scrambling aircraft against unidentified or misidentified targets,” the Pentagon report stated.

At the time, the Iranian air defense units were in a state of panic and tried to account for any kind of attack from Israel, fearing that a military aircraft from Israel might try to mimic a civilian airliner.

During the time period in question there was much discussion of a military response to Iran's nuclear program, both from Israel and the United States. Israel had bombed a nuclear reactor that was under construction in Syria in September 2007. The following year Israel held a major military air drill over the Mediterranean that Iran took as a serious threat for a potential attack.  

It was after this exercise that the Iranian military started training for a possible attack. Less than two weeks after the drill, according to a 2008 report by the Defense Intelligence Agency, fighter units were ordered to “conduct daily air-to-ground attack training (GAT) at firing ranges resembling the Israeli city of Haifa and the Israeli nuclear facility at Dimona."