The Stabilizing Role of Global Alliances in the Dynamics of Coalition Forming

Coalition forming is investigated among countries, which are coupled with short range interactions, under the influence of external fields produced by the existence of global alliances. The model rests on the natural model of coalition forming inspired from Statistical Physics, where instabilities are a consequence of decentralized maximization of the individual benefits of actors within their long horizon of rationality as the ability to envision a way through intermediate loosing states, to a better configuration. The effects of those external incentives on the interactions between countries and the eventual stabilization of coalitions are studied. The results shed a new light on the understanding of the complex phenomena of stabilization and fragmentation in the coalition dynamics and on the possibility to design stable coalitions. In addition to the formal implementation of the model, the phenomena is illustrated through some historical cases of conflicts in Western Europe.Comment: 19 pages, 12 figure

The effect of social balance on social fragmentation

With the availability of internet, social media, etc., the interconnectedness of people within most societies has increased tremendously over the past decades. Across the same timespan, an increasing level of fragmentation of society into small isolated groups has been observed. With a simple model of a society, in which the dynamics of individual opinion formation is integrated with social balance, we show that these two phenomena might be tightly related. We identify a critical level of interconnectedness, above which society fragments into sub-communities that are internally cohesive and hostile towards other groups. This critical communication density necessarily exists in the presence of social balance, and arises from the underlying mathematical structure of a phase transition known from the theory of disordered magnets called spin glasses. We discuss the consequences of this phase transition for social fragmentation in society