The Calculus of the Security Dilemma

Some scholars known as <italic>offensive realists</italic> claim that in the uncertainty of world politics, trust and cooperation between states is extremely unlikely. Others, such as <italic>defensive realists</italic>, claim that rational states are capable of finding ways to counteract the complications created by misperceptions and distrust, and to reduce uncertainty to levels where it no longer inhibits cooperation. In this paper, we construct a formal model to show how in some situations cooperation between states is indeed very unlikely: even in the presence of minor misperceptions, states fail to cooperate. We then ask whether diplomacy (modeled as cheap talk) is able to remedy the failure. We show that in many situations, allowing the countries to communicate prior to taking their actions does <italic>not</italic> enable them to cooperate.