ok, let me ask this question... (FReepers do not flame me, it is just a question)
Why would the U.S. be upset with Iran for reacting to an attack from the Kurds????
Turkey is different because it is a NATO ally and we have military bases in Turkey. And Turkey is not aiding the insurgents in Iraq.
Because Iranian aircraft - unlike Turkish aircraft - striking inside Iraq are a threat to all US forces in Iraq. The Iranian military - unlike the Turkish military - has been involved in attacks on the US military in Iraq.
Iran knew Bush/Cheney would view this (irrespective of who they were or were not attacking) as a grave threat to those forces and would likely respond according.
Iran knows something completely different about Obama. [And this is a fact and not a flame.]