As the Obama administration prepares to engage Iran diplomatically, one question is paramount: Who are the men with whom the White House hopes to reach accommodation? In "Khomeini's Ghost," British journalist Con Coughlin finds some troubling answers. He identifies the "Supreme Guide" Ayatollah Ali Khamenei as the final decision-maker in the Islamic Republic and thus the interlocutor for Obama. "The powers entrusted to the Supreme Guide . . . compare favorably to those claimed by Europe's fascist dictators . . . with the added benefit of claiming divine inspiration." Next to the supreme guide, Coughlin says the Islamic Revolutionary Guard,...