1. Outline War and its causes Balance of Power theory
World War I: history and explanation
World War II: history and explanation

2. Causes of war (Farnsworth, 1992)
Human nature
Balance of power theory – imbalances cause war
Efforts by states to build up own forces because they feel threatened
Number of states in system
Demands of domestic system
Nationalism
Bad leadership and policy choices

3. War and its causes

4. Balance of Power theory
Three definitions of “balance of power”
Description of distribution of existing power between states
Conscious policy and set of principles intended by states to achieve a balance of power
Unintended consequence of international system structure
“Secondary states … flock to the weaker side” (Waltz)
States sometime bandwagon rather than balance

5. Characteristics of polarity and balancing
Number of poles:
unipolar (hegemony)
bipolar
multipolar
Degree of polarization:
tightness
discreteness of poles
level of animosity
Relationship to war
imbalances cause war, equilibrium causes peace

6. World War I and its causes
Deep causes:
Increasing power of Germany
Less flexible alliance structure.
Intermediate causes
Concerns about encirclement and expansionist policies
Serb nationalism threatening to Austro-Hungary
Domestic German politics => adventurism and expansionism
Complacency about need to balance (as conscious policy)
Proximate causes
Poor leadership and diplomacy of Austro-Hungary, Russia, and Germany
Assassination came at bad time

7. Gavrilo Princip killing Archduke Francis Ferdinand 6/28/1914
Illustration from Italian newspaper.

8. Rising Nationalism
Rising popular participation
Collapse of Austria-Hungary
Domestic class conflict
Aggressive German Policy
Rise in German power
Bipolarity of Alliances
Loss of moderation in system process
Escalating Crisis
War in 1914
Source: Nye 2011, p. 93

9. World War II and its causes
Systemic level causes
Effects of First World War
WWI treaties too harsh and too lenient
State level causes
Poorly planned policies
Stalin pact with Hitler ignores downside risks
Strong nationalism in Germany and Japan
Economic collapse of Great Depression
US isolationism
Individual level causes
Hitler’s aggressive, expansionist, nationalist ideology
Appeasement and misperceptions by Chamberlain, et al.
Poor theory of Wilson and League of Nations
Japanese miscalculation of power vis-à-vis US