This research develops formal, game theoretic models pertaining to international systems. The research focuses on the problem of how states decide to join or avoid alliances. The models suggest four types of findings. First, international systems show tremendous stability in a bipolar context when the distribution of power reflects the distribution of territory held by the alliances. Second, when other alliances are introduced then the concept of a `balance of power` becomes exceedingly complex and new forms of modeling the process are needed. Third, the behavior of a nation is very sensitive to the distribution of power where there are three or more alliances in the international system. Finally, because of the complex dynamic between states, the natural propensity of states is to jump on the bandwagon or hide out when there is an international crisis. This latter finding is especially affected the amount of information nations have about the actions of others. All these findings point to the need for a broader understanding of the complex relations among states where there is no bipolar balance of power.