Donald Horowitz, Ethnic Groups in Conflict 2nd ed. (2000).

Horowitz argues that ethnic violence is both spontaneous and structured.  The key take home point of this book is that passion is a crucial component of any riot (particularly hatred) and that such passion does not detract from the fact that the ethnic riot is a highly patterned event. The role of passions has been neglected in the analysis of conflict (and in political science more generally).  Horowitz also puts forth the thesis that the selection of targets is more selective than has generally been understood. For Horowitz, target selection is a combination of calculation and passion.  Speaks directly to Skocpol’s analysis concerning the role of the state in facilitating/preventing ethnic violence.