The most publicly discussed link between economics and security is the relationship between economic performance and power. The underpinnings for this relationship come from the philosophical approach that sees political power stemming from economic power. Espoused at least since the 17th century by English Civil War philosopher James Harrington, these ideas saw their most well known expression in the philosophy of Karl Marx, who saw economic change driving political change. If economic structures determined politics then the link with security is clear. Carl von Clausewitz’s likened war to other areas of conflict within developed societies, such as commerce and politics: “It is a conflict of great interests which is settled by bloodshed, and only in that is it different from others.”