This book discusses the interaction between and the impact of overlapping actions by regional organizations while dealing with critical events. It compares all the sub-regions in South America and Africa from this perspective and creates new knowledge through cross-regional gleanings. The book analyses types of institutional interaction among regional organizations and the effects of overlapping actions on the coexistence or fracturing of regional processes. It examines and compares the dynamics of these interactions in both South America and Africa. The book contributes to the study of comparative regionalism by providing generalization and institutional learning based on a cross-regional approach. It gives to students, researchers and interested readers an understanding of the complexity of regional affairs in multi-organizational environments.