Perhaps the most dramatic incursion of the private sector into public policy is in the realm of security. Though the legitimate use of force is presumed to be the realm of the state, during the 1990s and into the new century the private sector's role in security has mushroomed. When Sierra Leone faced an insurgency in 1995, Valentine Strasser's government hired Executive Outcomes, a South African security firm, to train and support its troops. When the 1995 Dayton Accords required that the Bosnian military be rebuilt, MPRI (Military Professional Resources Incorporated), an American firm, was hired to advise and train the Bosnian military. When the World Wildlife Fund was faced with the possible extinction of the northern white rhino in a park in the Democratic Republic of Congo, it solicited a bid from Saracen, a South African and Angolan security firm to train and protect the guards. And global corporations, like British Petroleum, Exxon, DeBeers, and others, contracted with private security companies for site security and security planning all over the globe. A burgeoning transnational market for force now exists alongside the system of states. In this essay, I briefly describe this market and argue that it poses tradeoffs to the state control of violence—offering new tools for control even as it erodes others. Furthermore, the changes in the process of controlling violence that privatization brings with it pose tradeoffs to nonstate actors as well. Rather than simply shifting influence from governments to markets and civil society, the privatization of security is likely to engender changes in each, opening the way for new institutional innovations and the intensification of international change. The presence of private companies providing military services is not entirely new. In the period before the rise of the modern state, military contractors were common. Even in the …