The Basij militia is a central component of Iran's clerical regime and a supporter of hard-line conservative interests. It is a security organization that also engages in social and political activism. This study focuses on the group's rank-and-file members and looks at the organization's mechanisms for recruitment, participation, and training. Based in part on interviews with current and former Basij members, the article concludes with general observations about the organization and its internal practices.The Basij militia is an omnipresent feature of life in many Iranian cities. The orga- nization is one of the regime's largest social enterprises, encompassing somewhere between 1.5 to 15 million members, and has steadily evolved over the last two decades into a pillar of Iran's security establishment.1 There are seventeen separate Basij subor- ganizations (e.g., for university students, factory workers, government workers, engi- neers, etc.) and three types of Basij memberships: regular, active, and special. Regular members comprise the vast majority of the organization and are the lowest ranking, having undergone a minimal amount of training. Active members comprise a middle level and receive complete basic ideological coursework, and some military training. Special members are full-time Islamic Revolutionary Guards Corps (IRGC) soldiers who have been assigned to Basij units.2Although the Basij has steadily gained the attention of scholars, relatively little has been written about those who join the organization.3 To that end, this article explores general experiences of Basij members and specifically looks at how the organization's rank-and-file (both regular and active) members are recruited, what sort of incentives drive their participation, and what types of training and instruction they receive. The ar- ticle concludes with observations on three issues - the importance of social networks, the role of ideology in recruitment and retention, and the informality in leadership and structure - that give shape to the Basij, its membership, and its operations.This study is primarily based on interviews with former and current Basij mem- bers, conducted mainly in Tehran between November 2009 and July 2010. Due to the acute political tensions in Iran during that period (and since), the researchers and the subjects they interviewed requested to remain anonymous.4 Also for this reason, the in- terviews consciously avoided sensitive political topics (such as opinions on the regime's legitimacy and the Basij's role in suppressing popular unrest following the contested 2009 presidential election), and focused instead on less controversial aspects of general life in the Basij. Each interviewee was asked around fifty questions that covered non- political topics. These questions were divided into several broad categories that were designed to learn more about why individuals joined the Basij, the process of becoming a member, what sort of training they experienced (or were offered), what aspects of being a part of the organization they enjoyed, the types of activities that they took part in, and their general relationship with commanders. Although these interviews form a small data set, they nonetheless provide valuable glimpses into the internal dynamics of the Basij organization and the experiences of its members.SECURITY FORCES AND REGIME LOYALTYThe tsunami of popular unrest that has swept across the Middle East since 2011 has seriously challenged - and perhaps forever altered - some of the region's authoritarian regimes. While this turmoil has amplified the need for political reform in the region, it has also highlighted the risk of deploying security forces against spirited mass dissent. The extent to which governments deploy their security forces against popular protest often de- pends on a government's assessment of a particular force's loyalty to the regime against its members' sympathies for popular grievances. …