The planes are there to enforce the "on fly zone" which is supposed to keep Iraqi planes and gunships out of the north and south of the country.
Why? So Saddam can't massacre the Sunnis in the south and the Kurds in the north.
Why are the Turks killing Kurds? Because the Kurds want an independent country of their own (if they can ever agree among themselves who is in charge) and they want to make it out of part of Turkey and part of Iraq. I can understand the Turks reluctance to allow this.
This is not to say that the Turks haven't been a bit too enthusiastic in their zeal to protect their territorial integrity and political power.
Just telling a bit of the other side.
Bush Sr. had no mandate to take out Saddam and our laws forbid assassination as an instrument of foreign policy. We had hoped that his own people would overthrow him but it didn't work. Hence the current situation.

troll