Arabs and Persians are no different thank Yankees and Southerners, or Germans and French.

They're just people.

What has happened though is a perfect example of what happens when xenophobes get a hold of certain parts of a religion and meld it to their own means. Extremists can do to Christianity the exact same thing they did to Islam. In fact, if you review world history, pretty much every religion, at one point or another, has been under the control of their respective hard liners and used as a tool for ill. Thats the nature of human beings. My uncle is a muslim (Persian), and he's killed far fewer people than some of the members of the otherside of my family (Hard line Irish Catholics straight out of Derry). Heck, at one point Derry and Belfast were just as bad as Baghdad Tikrit, maybe even worse (right after the Easter Uprising or later on BLoody Sunday). Nobody judges all Catholics (or even all Irish) by the actions of the Unionists and Republicans, I can extend the same respect to other people's and religions.

Judge not the group, but the individuals.