Some have claimed that "War is too important to be left to the generals," but P. W. Singer asks "What about the business executives?" Breaking out of the guns-for-hire mold of traditional mercenaries, corporations now sell skills and services that until recently only state militaries possessed. Their products range from trained commando teams to strategic advice from generals. This new "Privatized Military Industry" encompasses hundreds of companies, thousands of employees, and billions of dollars in revenue. Whether as proxies or suppliers, such firms have participated in wars in Africa,...