Entropic properties of international systems

In this article the mathematical formula of entropy is used to evaluate the degree of anarchy specific to multipolar, bipolar, and balance of power international political systems. Several entropic properties characteristic to these systems are deduced, and it is proved that alliances decrease international systems' entropy. Each international system it is observed is characterized by a specific amount of structural strain, and that under the assumptions of structural neo‐realism the entropy and structural strain move in opposite ways. On the basis of these findings a few properties regarding the stability of international systems are divided and the effects of alliances on international structural strain are examined. In the last part of the paper theoretical conclusions are tested against three empirical cases – the Cold War bipolar system, the XIXth Century European system, and the current one. The article ends with several methodological suggestions regarding a possible generalization of the entropic model.