World War II: Causes, Development, and Key Events

Posted on Mar 6, 2025 in History

Causes of World War II

The Treaty of Versailles caused feelings of humiliation among the Germans and Italians, which led to:

  • A desire for revenge
  • The rise of dictatorial political systems
  • A new war to gain economic and political dominance in Europe

Totalitarian Regimes’ Desire for War

The fascist regimes developed expansionist policies, including:

  • Strengthening their armies
  • Encouraging militarism
  • An intense arms race

Escalating Aggression

In the 1930s, authoritarian states initiated hostile attacks:

  • Japan expanded at the expense of China, occupying Manchuria in 1931 and invading China in 1937.
  • Italy took possession of Ethiopia and Albania in 1935 (colonial expansion).
  • Italy and Germany took part in the Spanish Civil War, while France and Great Britain did not.
  • Germany’s policy of expansion aimed to create a Great Empire.

Germany’s actions included:

  • 1936: Violated the Treaty of Versailles by remilitarizing the Rhineland.
  • March 1938: Occupied Austria (Anschluss).
  • September 1938: Demanded Czechoslovakia hand over Sudetenland (populated by Germans).

Weakness of the Democracies

Due to the authoritarian regimes’ hostile policies, the democracies tried to insulate themselves (US) and focused on their own issues.

The League of Nations failed to respond to Nazi and fascist hostilities, eventually leading to war.

The Munich Conference (1938) was convened by Hitler because of:

  • Protests by France, Great Britain, etc., over his policy of expansionism.
  • Democracies accepted Hitler’s promises to expand no further.

Preparing for War: The Formation of Alliances

  • 1936: Germany entered into the Rome-Berlin Axis with Italy, renewed in 1939 as the Pact of Steel.
  • November 1936: Germany and Japan formed the Anti-Comintern Pact.
  • 1939: When Hitler seized the Danzig corridor, France and Great Britain promised support to Poland.
  • 1939: Hitler signed the Nazi-Soviet Pact to prevent the USSR from joining forces with France and Great Britain.
  • September 1939: Hitler invaded Poland.
  • In response, the Allies (Great Britain and France) declared war on Germany.

Development of the War

Axis Victories (1939-1941)

After the invasion of Poland (September 1939), Hitler launched a ‘lightning war’ (Blitzkrieg) using armored divisions and strong aerial support for surprised advances and quick attacks.

Poland collapsed after three weeks and was divided between Germany and the USSR (Nazi-Soviet Pact).

In 1940, Germany invaded:

  • Denmark
  • Norway
  • The Netherlands
  • Belgium
  • North and West France

Great Britain resisted:

  • Hitler’s air force bombed Britain (Battle of Britain), but Britain resisted, and Hitler aborted the invasion.
  • He ordered the blockade of the British (Battle of the Atlantic) to cut supplies.
  • Germany fought against Britain in the Mediterranean to cut supplies and weaken the enemy.
  • The German African Corps conquered North Africa, Yugoslavia, and Greece by April 1941.
  • June 1941: Operation Barbarossa – attacked the USSR, reaching the gates of Moscow and Leningrad. The USSR joined the Allies.
  • December 1941: Japan attacked Pearl Harbor, and the US entered the war.

Allied Offensives (1942-1945)

A decisive turn occurred in June 1942.

  • The Americans stopped the Japanese in the Pacific (Midway and Guadalcanal).
  • In North Africa, the British defeated the Germans (El Alamein).
  • An Allied army (Eisenhower) landed in French Africa and defeated the Germans in Tunisia by May 1943.
  • The German assault on Stalingrad (August 1942 to February 1943) was Hitler’s first major failure. After several months of siege, the Germans surrendered. The Soviets went on the attack, taking back Ukraine and ending the siege of Leningrad (January 1944).
  • Liberation of Europe began with the Normandy landings by British and American troops (June 1944). Part of France was liberated as the British and US defeated the Germans and continued from the West into Germany.
  • At the same time, the Russians moved from the east, pushing the Germans out of Poland, Romania, and Bulgaria, and heavily bombing German cities.
  • Both Allied armies met at the Elbe River (April 26, 1945). On April 30, Hitler committed suicide, and on May 8, Germany surrendered.

End of the Pacific War

  • In the Pacific, the Americans reconquered territories occupied by Japan, facing fanatical defense (kamikaze).
  • To force Japan’s surrender, Truman ordered the atomic bombing of Hiroshima and Nagasaki, devastating the cities (150,000 casualties). Japan surrendered on September 2, 1945, ending World War II.