Causes: Arms race, belief in military strength. Effects: Increased tensions, potential for large-scale conflict.

Causes: Desire for security, mutual defense pacts. Effects: Escalation of conflicts, involvement of multiple nations.

Causes: Economic competition, desire for resources, nationalism. Effects: Colonial exploitation, conflicts over territory.

Causes: Shared culture, language, and history. Effects: Desire for independence, unification movements, ethnic tensions.

Causes: Overproduction, decreased demand, stock market crash. Effects: Unemployment, poverty, rise of extremism.

Causes: Allied desire to punish Germany after WWI. Effects: German resentment, economic hardship, rise of extremist ideologies.

Causes: Desire to avoid war, belief that Hitler's demands were reasonable. Effects: Allowed Hitler to gain power, emboldened aggression, ultimately failed to prevent WWII.

Causes: To force Japan's surrender in WWII. Effects: Immediate devastation, long-term health consequences, end of WWII, beginning of the nuclear age.

Causes: Desire for international cooperation after WWII. Effects: Forum for diplomacy, peacekeeping operations, promotion of human rights.

Causes: Ideological differences between US and USSR, geopolitical competition. Effects: Arms race, proxy wars, division of Europe.

Led to the redrawing of European boundaries, the collapse of empires, and the rise of new nations. Set the stage for future conflicts.

Overthrew the Tsarist autocracy and led to the establishment of the Soviet Union, the world's first communist state.

A severe worldwide economic depression that led to widespread unemployment, poverty, and social unrest.

The deadliest conflict in human history, resulting in the deaths of millions and the reshaping of the global political order. Led to the creation of the UN.

The systematic genocide of European Jews and other minority groups by Nazi Germany during World War II.

Led to the establishment of the People's Republic of China under the leadership of Mao Zedong.

Brought the United States into World War II, shifting the balance of power against the Axis powers.

Mass slaughter of Tutsi in Rwanda by members of the Hutu majority government.

The systematic destruction of the Armenian people by the Ottoman government.

Meetings of the Allied victors, following the end of World War I to set the peace terms for the defeated Central Powers.

WWI: Militarism, alliances, imperialism, nationalism. WWII: Unresolved issues from WWI, rise of fascism, appeasement.

WWI: Redrawing of European map, League of Nations. WWII: UN, Cold War, decolonization.

Fascism: Nationalistic, authoritarian, private property allowed. Communism: Internationalist, totalitarian, state-controlled economy.

League of Nations: Weak, lacked US participation, failed to prevent WWII. United Nations: Stronger, more inclusive, more effective at peacekeeping.

Industrialization fueled militarism and imperialism, creating more powerful nations. New weapons led to drastic increases in casualties and destruction.

Marshall Plan: US aid to rebuild Western Europe, prevent communism. Warsaw Pact: Soviet response, military alliance of Eastern European nations.

Mexican Revolution: Primarily a social and political revolution focused on land reform. Chinese Revolution: Communist revolution focused on overthrowing the existing government and establishing a communist state.

Short-term: Widespread unemployment, poverty, bank failures. Long-term: Rise of extremist ideologies, increased government intervention in the economy, WWII.

India: British colonialism, economic exploitation, cultural suppression. Africa: European colonization, resource extraction, political domination.

First World War: Collapse of empires, creation of new nations, rise of new ideologies. Second World War: Division of Europe, rise of superpowers, beginning of the Cold War.