About these notes. This is the sub-topic lookup version. For the full narrative lesson, use the Walk-through. For active recall, use the MCQ Quiz.
Likely exam angles. A 30-mark essay deploys the theories as competing readings of a contemporary case (often the war in Ukraine), shows where they agree and disagree, and judges which best explains it - never picking one and ignoring the rest.
International relations theory is not decoration - every claim about why a state acted rests on a theoretical assumption. "Russia invaded Ukraine to protect its security" is a realist claim; "because it rejected the liberal order" is a liberal or constructivist one. The interpretation comes before the conclusion.
States are the dominant actors; they operate in anarchy; they pursue national interest defined as security and power; they cannot fully trust one another; war is a recurring feature. Three variants:
| Variant | Thinker | Core claim |
|---|---|---|
| Classical | Morgenthau (1948) | State behaviour is rooted in human nature - a Hobbesian drive for power and self-preservation. Statesmen think in terms of interest defined as power. |
| Neo / structural | Waltz (1979) | Not human nature but the structure of anarchy drives behaviour; any state would act similarly in that structure. Great powers balance against the most powerful. |
| Offensive | Mearsheimer (2001) | States seek hegemony, not just security, because they can never be sure of others' intentions. Mearsheimer argues NATO expansion provoked Russia over Ukraine. |
Liberalism holds that cooperation is possible and durable. States are not the only actors (IGOs, NGOs, MNCs matter), and several mechanisms tame anarchy:
A liberal reads the EU as proof that institutions enable lasting cooperation, and reads sanctions on Russia as collective enforcement rather than mere power politics.
There is more order in international politics than realists admit, because states form a society of states sharing norms, rules and institutions (diplomacy, international law, the balance of power). Order coexists with anarchy. The coordinated sanctions on Russia look, to the English School, like a society of states punishing a rule-breaker.
Identities and ideas shape what states want in the first place - interests are not fixed by material structure but socially constructed. "Anarchy is what states make of it" (Wendt). A constructivist explains Russia's invasion through identity and a rejection of the post-1991 European order, not just the balance of power.
| Theory | Reading of the war in Ukraine |
|---|---|
| Realism | A great power acting on security and the balance of power; Mearsheimer blames NATO expansion. War is normal in anarchy. |
| Liberalism | A breakdown of interdependence and institutions; the Western response shows collective enforcement and the value of alliances. |
| English School | A society of states punishing a member that broke the rules through coordinated sanctions and diplomatic isolation. |
| Constructivism | A clash of identities and ideas - Russian self-image and rejection of the liberal European order - not just material interest. |