‘When you think of private security and international politics, what is the first image that springs to mind?’ Over the past few years, we have asked this question dozens of times to groups and audiences in numerous countries and contexts. The answers have been remarkably uniform, usually revolving around burly men in combat fatigues, wrap-around sunglasses and automatic weapons. This is no great surprise: the return of mercenary activities in Angola and Sierra Leone in the immediate aftermath of the Cold War and the extensive involvement of private contractors in both Iraq and Afghanistan have justifiably placed corporate soldiers and private military companies (PMCs) at the centre of much public debate and scholarly enquiry.

Yet the growth and impact of private security extends far beyond the spectacular activities of corporate soldiers and the increased involvement of private companies in warfare and military affairs. In almost every society across the globe, private security has become a pervasive part of everyday life, and in many countries private security personnel now outnumber their public counterparts by a considerable margin. Recent decades have also seen the emergence of private security companies (PSCs) that operate on a global scale. The world’s largest PSC, Group4Securicor (G4S), is present in over 110 countries, and, with 585,000 employees, it is the biggest employer on the London Stock Exchange. Engaged in the seemingly mundane protection of life and assets – the guarding of workplaces, shopping malls and universities, the monitoring of alarms and closed-circuit televisions (CCTVs), the provision of risk assessment and management – this aspect of security privatization has become so integrated into our daily activities of work and leisure as to go mostly unnoticed. Perhaps for this reason, it is also the untold story of security privatization in international politics.