Emboldened by its nuclear deal with the world powers, Iran is already seeking to enfold in its embracing wings the Arab and Islamic region. Iran's capacity for intrusions having been starved by years of sanctions. Now, with the lifting of sanctions, Tehran's appetite for encroachment has been newly whetted -- and its bull's-eye is the West Bank. Iran has, in fact, been meddling for many years in the internal affairs of the greater region. It has been party to the civil wars in Yemen and Syria, and, through the Shiite Muslims living there, continues actively to undermine the stability of...