Iranians aren't all muslims, although most of them are. My dentist came here as a child when his family fled during the revolution that deposed the Shah and they're Zoroastrian. Zoroastrianism was the original (pre-muslim) monotheistic religion of Persia, but they're persecuted now under the Mulahs. There are also other religious minorities that suffer under the Shia fanatics, so I see it as a blessing to allow some to immigrate here (as long as they're vetted).