Three-body interactions in sociophysics and their role in coalition forming

An study of the effects of three-body interactions in the process of coallition formation is presented. In particular, we modify an spin glass model of bimodal propensities to include a particular three-body hamiltonian that reproduces the main features of the required interactions. As an application, we analyze a simplyfied model of the Iraq war , which shows that three-body effects are sometimes more important than friendship.