End of multipolar 'balance of power' system in Europe:
- Two great alliances of European powers clash
- France/ Britain/ Russia/ Italy v Germany/ Austro-Hungary/ Ottoman empire.
World War I ends in social collapse, mutiny, revolution:
The Russian Revolution and the rise of Communism
* Unstable economic recovery followed by the Great Depression (1929)
* The rise of Fascism.
* Intensifying international rivalries:
Imperial Protectionism, economic nationalism
* Ideological conflict – communism vs fascism vs liberal democracy
* Rise of Non-European powers (US, Japan)
* Failure of League of Nations, and 'appeasement' at Munich Conference (1938).