System in this context refers to the modes, rules, and nature of reciprocal influence which structure the interaction between states. Five kinds of system may be mentioned: Coalitions (temporary and permanent); Supranational Organization; Bilateral; Multilateral (unorganized); and ordination-subordination (imperial relationships and satellites).
Once again, the way these interactions and relationships arise and the particular form or substance they take would seem to be explainable in terms of the way the decision-makers in the participating political organisms "define their situation". As we have said elsewhere, there seem to be only two ways of scientifically studying international politics:
1. The description and measurement of interaction;
2. Decision-making - the formulation and execution of policy. Interaction patterns can be studied by themselves without reference to decision-making except that the why of the patterns cannot be answered.