The effects of individual state action often touch on the possibilities and limits of other states' actions and their welfare. Prominent examples are global problems such as climate change, protectionist trade policies and questions of national defence efforts within military alliances. States determine the outcome of their actions in interactive strategic decision-making situations.

In scientific terms, the aim is to explain observable outcomes of action from the logic of the goals of individual states and to explore the connection between institutional circumstances and these outcomes of action.