Perhaps the best book out there in explaining the functioning of the political system of the Islamic Republic of Iran. Not only does it offer one of the most lucid analyses of the functions, mandates and workings of the different clerical councils and other institutions in the political system, it also sheds light on topics often neglected in the contemporary political science on Iran, i.e. dissident clergy, militant opposition in exile, relations between intelligence organizations and the judiciary, the governmental newspapers etc.
Based on meticulous research in Persian, Arabic, German and English. Unfortunately, no study has appeared ever after this one that succeeded in providing such an extensive, lucid and well-researched overview.