World Wars: Causes, Phases, Treaties and Consequences

Causes of World War I

The reasons for the outbreak:

• Territorial claims of different countries, such as Russia, and economic rivalries.
• Austria-Hungary tensions and competing ambitions, especially between Germany and the United Kingdom.
• Colonial interests and the formation of opposing alliances: the Triple Alliance and the Triple Entente.

Characteristics of the Conflict

Key characteristics:

• New weapons and defensive systems, which transformed combat.
• Women entering the workforce in large numbers to support the war effort.
• The economy became centered on the war; its main goal was the production of weapons.
• Propaganda played a major role in maintaining the morale of the population.

Phases of World War I

Phases of conflict:

• War of movement (1914): Germany carried out the Schlieffen Plan.
• War of position (1915–1916): New weapons and trench systems prevented rapid advances.
• Key developments (1917): The Russian Revolution occurred and the USA entered on the side of the Allies.
• The end of the war (1918): The Allied countries prevailed, aided significantly by U.S. material and manpower.

Paris Peace Treaties and Wilson's Fourteen Points

The Peace of Paris: The Paris peace settlements were signed and reflected, in part, President Wilson's Fourteen Points. President Wilson promoted the idea that the U.S. people supported lasting peace and self-determination.

Major treaties included:

• The Treaty of Versailles with Germany.
• The Treaty of Trianon with Hungary.
• The Treaty of Saint-Germain with Austria.
• The Treaty of Neuilly with Bulgaria.
• The Treaty of Sèvres with the Ottoman Empire (the Ottoman/Turkish territories were restructured).

Consequences of World War I

Consequences of the war: Great loss of life; major social and territorial changes; and economic disaster for much of Europe.

Causes of World War II

Causes:

• The territorial expansion of totalitarian states undermined international peace.
• Democratic nations (the UK and France) pursued a policy of appeasement toward aggressive powers.
• The formation of the Axis alliance: Berlin – Tokyo – Rome.
• Germany's invasion of Poland in 1939 provoked the UK and France to declare war on Germany.

Phase One of World War II (1939–1941)

1st phase: Germany invaded Poland in 1939. Germany conquered Norway and Denmark (1940) and defeated Belgium and France. It failed to defeat Britain in the Battle of Britain. Germany was joined by Axis partners such as Hungary, Slovakia and Bulgaria. In 1941 Germany invaded Yugoslavia and Greece and then attacked the USSR, which resisted. The United States entered the war after the attack on Pearl Harbor.

Phase Two of World War II (1942–1945)

2nd phase: The Allies, led by President Roosevelt and with Soviet cooperation under Stalin, coordinated offensives and defeated the Axis. Germany and Italy were defeated in North Africa. In 1944 the Normandy landings opened a Western front. Soviet forces took Berlin in 1945. Adolf Hitler died that year. Japan continued to resist until the United States dropped atomic bombs on Hiroshima and Nagasaki.

Consequences of World War II

Consequences: The war killed more than 50 million people. Some groups, such as Roma (Gypsies) and Jewish people, were targeted and suffered genocide and near destruction in some regions. In international relations, the power of European countries was greatly reduced while the United States and the USSR emerged as superpowers.

Territorial effects: Germany lost territory; the political map of Europe and the colonies was reshaped. Japan was occupied after the war and democratic reforms were imposed during the occupation.

Economic effects: Europe was left deeply in debt and economically devastated. The United States was less physically affected and helped rebuild Europe through the Marshall Plan.