Introduction

This introductory chapter provides an overview of alliances among ideological enemies. Members of these alliances are perpetually torn by two sets of powerful contending forces. Shared material threats push these states together, while the effects of ideological differences pull them apart. Because of these opposing forces for and against cooperation, members of cross-ideological alliances are simultaneously friends and enemies. They are “frenemies.” This book claims that the values of two ideological variables in addition to that of ideological enmity play the key role in determining when either the rivalry or common-interest dimension of frenemy relationships is likely to prevail. The first variable is the level of regime or ideological vulnerability in the members of a potential frenemy coalition. The second variable is the particular configuration of ideological distances that exists among potential frenemy allies and their shared material threat.