Because Iran has always respected Iraq sovereignty, especially during the 10 year long failed attempt to invade and conquer them...
Iran is a shame to Islam, their transparent lies show their weakness in Islam, a true Muslim would be able to lie much better. Therefore it is a call to Jihad to overcome their false Islam and subjugate them to true Islam by death and destruction.
(Spoken from a Muslim perspective)
Nothing like living with Palestinians as your neighbors for a decade to show you the dark and twisted basement of their souls...