An International Relations Theory

When do states go to war?

What common themes did you notice in the Melian Dialogue and the Munich Conference?
Why do you think Athens decided to invade Melos?
Why do you think Hitler invaded Czechoslovakia after agreeing not to?
Realism offers answers to these questions. It is one framework for predicting when states will go to war, and it explains why states are so inherently aggressive.

Five Core Assumptions of Realism

According to John Mearsheimer
  1. The international system is anarchic
  2. States possess some inherent military capability
  3. One state can’t know another state’s intentions
  4. The primary goal of states is survival
  5. States are rational actors

Assumption 1: Anarchy

  • Anarchy refers to the structure of the international system

    • When IR scholars refer to “anarchy,” they do not mean chaos or disorder
    • States have no higher authority to appeal to during crisis. No government over governments
  • 911 Scenario

  • Anarchy creates incentive for distrust and self-help

    • “God helps states that help themselves.” - John Mearsheimer

Assumption 2: Offensive Military Capabilities

  • All states possess some military capability

  • Thus, by virtue of existing, a state in the international system poses a threat to other states via its military.

  • Because of this, fear is a characteristic of life in the international system. States do and should fear the capabilities of other states, according to realists.

    • To do otherwise is naive.
    • Today’s allies are tomorrow’s enemies, and vice-versa.

Assumption 3: Unknown Intentions

  • A state can never be sure that another state will not use its military offensively.

    • Specifically highlights the uncertain nature of alliances
    • Consider Sparta in the Melian Dialogue: Why did they not help their ally, the Melians?
  • Does not necessarily mean all states are aggressive - the point is, it’s impossible to know.

  • Essentially, assumption 2 is all states have aggressive capacity, and assumption 3 pertains to the unknowability of aggressive intention.

  • Result: States should prepare for the worst.

Assumption 4: Survival is the Primary Goal of States

  • The emphasis here is that - before ANYTHING else - states are concerned about survival.

    • Implications: Tertiary motives like ideology, alliances, trade, international commitments, etc. are only important after a state’s survival is secured. Survival is always first.
    • Consider Maslow’s Hierarchy of Needs, applied to states.
  • Joseph Stalin: “We can and must build socialism. But in order to do so we first of all ahve to exist.”

Assumption 5: States are Rational Actors

  • Emphasis here is that states are aware of both the implications of their own actions and (more to the point) the implications of other states’ actions and preferences.

  • Example: If a state builds up its military, other states may grow nervous due to the implications for their own security.

Three Predictions from Realist Assumptions

  1. Fear
  2. Self-Help
  3. Power Maximization