Since 1997 President Muhammad Khatami and the reformists in Iran have won elections overwhelmingly, but they continue to face adamant opposition ensconced in the judiciary, the military, and the security forces -- not to mention the preemptively powerful office held by Ayatollah Khamenei. As if these legally constituted forces were not challenge enough, a number of extremist groups continue to use intimidation, beatings, and even assassination to oppose those who would dare to call for reform. Worse, they have ties to government officials. In this short book, Rubin identifies these groups, describes their antecedents, and traces their links to government officials. Much remains obscure, including even the numbers involved, which seem to be only a few hundred. Rubin concludes that no "diplomatic or economic carrots" should be offered to Iran until its government reins in these vigilantes. But is the government itself not divided between Khatami's followers and the Islamist conservatives, many of whom want no ties with the West anyway?