Iranians have an national obsession, inferiority complexes and hatred for Arabs for the Muslim Arab conquest of Iran and centuries of Arab rule, the everlasting change of religion, culture, linguistic (Farsi is almost an Arabic dialect as a consequence), scripture, names, surnames (most of which are Arabic in origin), even genetical impact etc. The most hardcore Iranian nationalists (the majority abroad and I suspect the majority of their irreligious youth nowadays) claim that Iran has been an Arab colony for the past 1400 years and anything remotely related to Islam is an "Arab virus". You see such similar rhetoric from certain Iranian users here on PDF as well. They know who they are themselves.
Most Iranians are only Muslim by name, they value their pagan traditions such as Nawruz (ancient Semitic/Babylonian spring festival that they copied in pre-Islamic times like almost everything else), most of them (young generations) have a deep hatred for Islam (which they associate with Arabs) and they already have the lowest mosque attendance in the entire Muslim world.
Arab regimes are retarded if they trust such an entity especially considering the past 43 years of history.
I guess they have to learn it the hard way when they don't listen to the majority sentiments of Arabs in regard to that entity.