To date, most discussion of security privatization in international politics has been focused on the role of private military companies and mercenaries. This article seeks to shift the focus away from the battlefields and toward the less spectacular privatization and globalization of commercial private security. Drawing on Saskia Sassen’s notion of state ‘‘disassembly,’’ we situate the growth of private security within broader shifts in global governance. Pointing to the weakness of seeing the rise of private security as an erosion of state power and authority, we show instead a re-articulation of the public ⁄private and global ⁄local distinctions and relationships into what we term ‘‘global security assemblages.’’ Analyzing the role of private security in two such assemblages in Sierra Leone and Nigeria, we show how a range of different security agents and normativities interact, cooperate and compete, to produce new institutions, practices and forms of security governance. Global security assemblages thus mark important developments in the relationship between security and the sovereign state, structures of political power and authority, and the operations of global capital. Spurred by the apparent return of mercenary activities in Africa at the end of the Cold War, and given further impetus and urgency by the substantial involvement of private military contractors in Afghanistan and Iraq, the privatization of security has become one of the most controversial issues in contemporary international politics. Once obscure companies such as Blackwater, Triple Canopy, and Erinys have joined with tales of ‘‘neo-mercenaries’’ like Executive Outcomes in Sierra Leone and Simon Mann’s attempted coup in Equatorial Guinea in 2004, to become the focus of widespread journalistic coverage, increasingly sophisticated scholarly analysis, as well as popular books, entertainment and Hollywood films. Yet the privatization of security and its consequences go well beyond the activities of the private soldier. Away from the battlefields, in the day-to-day activities of ordinary life, private security has also become ubiquitous. Less spectacular than the ‘‘return of the dogs of war,’’ commercial private security activities, ranging from manned guarding and alarm installation, to risk analysis and surveillance, have expanded at a phenomenal rate. Worldwide, the commercial private security market is now valued at $165 billion, and its growth is forecast to continue at an annual rate of 8% for the foreseeable future (Securitas 2007). Indeed, what was once described as a ‘‘quiet revolution’’ in security provision has become global in scope (Shearing and Stenning 1981).