THE SECOND WORLD WAR (1939–1945)

INTRODUCTION

The Second World War (1939–1945) was the most destructive conflict in human history, involving major world powers and causing unprecedented military, economic, and human losses. It emerged from unresolved tensions after World War I, the rise of totalitarian regimes, global economic instability, and aggressive expansionism by Germany, Italy, and Japan. The conflict radically reshaped international relations, leading to the decline of European imperial powers, the emergence of the United States and the Soviet Union as superpowers, and the creation of the United Nations.

ORIGINS OF THE WAR

THE CONSEQUENCES OF WORLD WAR I AND THE TREATY OF VERSAILLES

The Treaty of Versailles (1919) imposed harsh territorial, military, and economic penalties on Germany. These conditions fostered resentment and revanchism, providing fertile ground for the rise of extremist ideologies.

THE GREAT DEPRESSION AND POLITICAL RADICALIZATION

The global economic crisis of 1929 destabilized democratic governments. Mass unemployment, poverty, and social unrest allowed totalitarian regimes to gain support by promising national recovery and expansion.

THE RISE OF TOTALITARIAN REGIMES

• Germany (Nazi regime): Adolf Hitler came to power in 1933, creating a totalitarian state and advocating racial supremacy, rearmament, and territorial expansion (Lebensraum).
  
  

• Italy (Fascist regime): Mussolini strengthened authoritarian rule and pursued imperial ambitions in Africa.
  
  

• Japan (Military authoritarianism): Expansion in Asia intensified, including the invasion of Manchuria (1931) and war with China (1937).
  
  

FAILED DIPLOMACY AND THE POLICY OF APPEASEMENT

European powers, especially Britain and France, attempted to maintain peace through concessions, allowing:

• German reoccupation of the Rhineland (1936)
  
  

• Annexation of Austria (Anschluss, 1938)
  
  

• Disintegration of Czechoslovakia after the Munich Agreement (1938)
  
  

These concessions emboldened Hitler’s expansionist agenda.

THE GERMAN-SOVIET PACT

The Molotov–Ribbentrop Pact (August 1939) guaranteed non-aggression between Germany and the USSR and secretly divided Eastern Europe into spheres of influence. This removed the last obstacle to German invasion.

THE OUTBREAK AND EARLY PHASE OF THE WAR (1939–1941)

THE INVASION OF POLAND

On 1 September 1939, Germany invaded Poland using Blitzkrieg tactics. Britain and France declared war two days later.
The Soviet Union invaded eastern Poland shortly afterward, completing its dissolution.

THE GERMAN ADVANCE IN EUROPE

Between 1940 and 1941, Germany conquered:

• Denmark and Norway
  
  

• Belgium, the Netherlands, and Luxembourg
  
  

• France, establishing the Vichy regime
  
  

The rapid collapse of France shocked the world.

THE BATTLE OF BRITAIN

Germany attempted to force British surrender through massive bombings (the Blitz). The Royal Air Force resisted successfully, marking Hitler’s first major defeat.

THE MEDITERRANEAN AND NORTH AFRICA

Italy’s failures in North Africa forced German intervention under General Rommel, leading to intense fighting with British forces.

GLOBALIZATION OF THE CONFLICT (1941–1943)

OPERATION BARBAROSSA

Germany launched a massive invasion of the Soviet Union on 22 June 1941, aiming to destroy communism and gain resources.
Initial successes halted due to:

• Harsh winter
  
  

• Stretched supply lines
  
  

• Soviet resistance
  
  

The failure to take Moscow marked a turning point.

THE WAR IN ASIA AND PEARL HARBOR

On 7 December 1941, Japan attacked Pearl Harbor, prompting U.S. entry into the war.
Japanese forces occupied large parts of Southeast Asia and the Pacific.

THE ALLIED RESPONSE

The United States, the United Kingdom, and the Soviet Union formed the Grand Alliance.
Key strategies included:

• “Germany first” doctrine
  
  

• Material support to allies (Lend-Lease Act)
  
  

• Coordinated military planning in major conferences (Tehran, Casablanca)
  
  

TURNING POINTS (1942–1943)

STALINGRAD

One of the deadliest battles in history (1942–1943).
The Soviet victory marked the beginning of the German retreat.

EL ALAMEIN

British forces under Montgomery defeated Rommel in North Africa (1942), ending Axis expansion there.

MIDWAY

The U.S. Navy defeated Japan (June 1942), shifting the balance in the Pacific.

ALLIED LANDINGS IN NORTH AFRICA

Operation Torch (1942) allowed the Allies to take control of the region and prepare for Mediterranean operations.

THE FINAL PHASE AND ALLIED VICTORY (1943–1945)

ALLIED LANDINGS IN ITALY

Sicily (1943) and mainland Italy were invaded. Mussolini fell, but German forces prolonged the campaign.

D-DAY AND THE LIBERATION OF FRANCE

Operation Overlord (6 June 1944) opened a Western front. Paris was liberated in August 1944.

ADVANCE INTO GERMANY

Soviet forces reached Berlin in April 1945.
Hitler committed suicide on 30 April.
Germany surrendered unconditionally on 8 May 1945.

THE END OF THE WAR IN ASIA

After heavy fighting and U.S. island-hopping:

• Atomic bombs were dropped on Hiroshima and Nagasaki (August 1945).
  
  

• Japan surrendered on 2 September 1945.
  
  

CONSEQUENCES OF THE SECOND WORLD WAR

HUMAN AND SOCIAL CONSEQUENCES

• Over 70 million deaths, including civilians and soldiers
  
  

• The Holocaust and systematic genocide
  
  

• Massive displacement of populations
  
  

• Long-term demographic imbalances
  
  

POLITICAL CONSEQUENCES

• Emergence of the United States and the USSR as superpowers
  
  

• Beginning of the Cold War
  
  

• Division of Germany
  
  

• Creation of the United Nations (1945)
  
  

• Decolonization movements accelerated worldwide
  
  

ECONOMIC CONSEQUENCES

• Widespread destruction in Europe and Asia
  
  

• U.S. economic dominance
  
  

• The Marshall Plan (1948) rebuilt Western Europe
  
  

• Expansion of international economic institutions (IMF, World Bank)
  
  

CULTURAL AND IDEOLOGICAL CONSEQUENCES

• Human rights movements gained strength
  
  

• War crimes trials (Nuremberg, Tokyo)
  
  

• Development of nuclear weapons reshaped global security
  
  

KEY DATES, BATTLES, FIGURES, AND AGREEMENTS (1939–1945)

KEY DATES

• 1 September 1939: Invasion of Poland
  
  

• 1940: Fall of France
  
  

• 1941: Operation Barbarossa; Pearl Harbor
  
  

• 1942–1943: Stalingrad
  
  

• 6 June 1944: D-Day
  
  

• 8 May 1945: German surrender
  
  

• 2 September 1945: Japanese surrender
  
  

MAJOR BATTLES

• Battle of Britain (1940)
  
  

• Operation Barbarossa (1941)
  
  

• Stalingrad (1942–1943)
  
  

• El Alamein (1942)
  
  

• Midway (1942)
  
  

• Normandy landings (1944)
  
  

• Battle of the Bulge (1944–1945)
  
  

• Okinawa (1945)
  
  

KEY POLITICAL AND MILITARY FIGURES

• Adolf Hitler, Benito Mussolini, Hideki Tojo
  
  

• Winston Churchill, Franklin D. Roosevelt, Harry Truman
  
  

• Joseph Stalin
  
  

• Dwight D. Eisenhower, Erwin Rommel, Bernard Montgomery
  
  

• Douglas MacArthur, Chester Nimitz
  
  

MAJOR AGREEMENTS AND CONFERENCES

• Munich Agreement (1938)
  
  

• Molotov–Ribbentrop Pact (1939)
  
  

• Atlantic Charter (1941)
  
  

• Casablanca Conference (1943)
  
  

• Tehran Conference (1943)
  
  

• Yalta Conference (1945)
  
  

• Potsdam Conference (1945)