World War II: Origins, Key Phases, and Global Impact

World War II: A Global Conflict (1939–1945)

World War II was a major military conflict that took place between 1939 and 1945. It broke out in Europe on September 1, 1939, when Germany invaded Poland. In 1941, the USA and the USSR joined the conflict. The war involved almost all European countries, Japan, the US, China, and European colonies in North Africa, Asia, and Oceania. This conflict was characterized by total war, where countries employed all available human, military, economic, and scientific resources to defeat the enemy.

Causes of the Conflict

• National Discontent: Following World War I, Germany was unhappy with the Treaty of Versailles (losing territory to Poland and Czechoslovakia), and Italy felt slighted by not receiving desired Mediterranean territories.
• Economic Protectionism: Nations turned to autarky to reduce imports during the Great Depression of the 1930s.
• Expansionist Policies: Germany, Italy, and Japan sought to aggressively expand their territories.
• Appeasement Policies: Great Britain supported a policy of appeasement toward Germany and Italy.
• Failure of the League of Nations: Created to maintain peace, the League was unable to meet its objectives in the years prior to the war.

Territorial Expansion

• Japan in Asia: Occupied Manchuria and northern China.
• Italy in Africa: Occupied Abyssinia and Albania.
• Germany: 1935 (Saar reincorporated), 1936 (occupied Rhineland), 1938 (peaceful annexation of Austria and the Sudetenland via the Munich Conference), 1939 (occupied Czechoslovakia, breaking the Munich agreement).

Formation of Opposing Sides

1. The Axis Powers

In 1936, Germany and Italy formed a pact. Japan joined the Anti-Comintern Pact, and by 1940, the Berlin-Rome-Tokyo Axis was established. Germany also signed a non-aggression pact with the USSR in 1939 (the Molotov-Ribbentrop Pact) to divide Poland.

2. The Allies

Great Britain signed a mutual support agreement with France in 1939 after Germany attempted to annex Danzig. The core alliance included Great Britain, France, and Poland.

Development of the War: First Phase

The Axis powers launched offensives across Europe, Africa, and Asia. Germany achieved various victories using the Blitzkrieg (lightning war) strategy—a combination of surprise, air, and land attacks that provided a decisive advantage.

Europe

In 1940, after the invasion of Poland, Germany occupied Denmark and Norway to the north, and the Netherlands, Belgium, Luxembourg, and France to the west. In 1941, Germany invaded the USSR with the objective of occupying Moscow, controlling wheat in Ukraine, and securing oil wells in the Caucasus. Stalin joined the Allies; although Germany reached Leningrad and the outskirts of Moscow, the harsh winter caused the offensive to fail. Additionally, Germany conquered Greece and Crete, while Hungary, Romania, Slovakia, and Bulgaria joined the Axis to support the offensive against the USSR.

Africa

In 1940, Italy attacked Egypt (held by Great Britain). The Africa Korps, led by Rommel, utilized Panzer tanks and Stuka planes to challenge British control of the Suez Canal.