The second four volumes of this eight-volume set provide comprehensive coverage of the factors that determined the evolution of world system in the twentieth century. With over 80 thematically organized articles selection by Michael Cox, Volumes 5-8 explore what happened following the collapse of the bipolar order in 1989 and the implications of this transition for the conduct of international relations. Together the volumes combine to provide an unparalleled resource providing broad coverage of the subject with historical depth and contemporary relevance.