Imperialism
The White Man's Burden
Total War
Nationalism
Liberalism
Conservatism
Militarism
Fascism
Populism
Pacifism
Diplomacy
Appeasement
Ultimatum
Nation-States
Hegemony
Great Powers
Domestic
Sovereignty
Authoritarianism
Totalitarianism
Trench Warfare
Attrition Warfare
Blitzkrieg
Leapfrogging
The Holy Roman Empire
Industrial Revolution
The Treaty of Versailles
League of Nations
October Revolution
Molotov-Ribbentrop Pact
Operation Barbarossa
Holocaust
Pearl Harbor
The Second Battle of El Alamein
Operation Husky
Bombing of Hiroshima and Nagasaki