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.
That is called a political reality. In terms of foreign policy, most of the time you don’t get to choose between good and evil but rather, bad and worse. We work behind the scenes with Turkey to try to alter their behavior rather than confront them publicly. Iran is a different story. It is called differentiation. Hell, we used to be an ally of Stalin in order to defeat Hitler.
In part the question is resolved in the context that Iran is itself a terrorist nation and Turkey is not...........
Iran doesn't kill Jihadi terrorists. They ARE Jihadi terrorists. They also fund such groups from around the globe so that there might be a chance some of the US military might get killed or better yet, innocent American civilians! Remember the old saying (well okay, maybe YOU don't), but it goes: One man's terrorist is another man's freedom fighter. We don't much care what Iran claims it's doing outside their own borders. We pretty much do know that whatever they are doing it will have some direct and harmful consequences on our military, our civilians or our national infrastructure, to include the economy. It is not in our best interests to let them go running all over causing such trouble. But OhhhhhBaby is going to let them do just that.
One
Big
A$$
Mistake
America!