With the invasion of Poland on September 1, 1939, World War II officially began. The first two years of the war were marked by rapid German victories in Europe, the expansion of the conflict into multiple regions, and the eventual involvement of the United States. This chapter explores the key events from 1939 to 1941, highlighting how the war escalated from a European conflict to a truly global struggle.
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1. The German Invasion of Poland (September 1939)
The war began with Germany's Blitzkrieg (Lightning War) strategy, a military tactic that emphasized speed, surprise, and overwhelming force. German forces, supported by tanks and aircraft, rapidly overran Poland.
The Blitzkrieg Strategy
Blitzkrieg relied on:
Coordinated air and ground attacks – German Luftwaffe (air force) bombed key Polish defenses and infrastructure.
Fast-moving Panzer divisions – German tanks penetrated enemy lines quickly.
Encirclement tactics – Polish forces were surrounded before they could organize an effective defense.
Poland fought bravely but was outmatched. On September 17, 1939, the Soviet Union invaded Poland from the east, fulfilling its secret agreement with Nazi Germany under the Molotov-Ribbentrop Pact.
By October 6, 1939, Poland was fully occupied, with Germany and the Soviet Union dividing it between them. The world realized that Hitler's ambitions were far greater than what appeasement had hoped to contain.
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2. The Phony War (October 1939 – April 1940)
Despite Britain and France declaring war on Germany, there was little immediate fighting on the Western Front. This period, known as the Phony War (Sitzkrieg), saw both sides preparing for future battles but engaging in limited direct conflict.
Britain and France reinforced their defenses along the Maginot Line, a heavily fortified border in eastern France.
Germany, meanwhile, prepared for its next phase of expansion but did not launch major attacks in the west.
British forces prepared for German aggression but remained largely inactive.
This lull ended abruptly in April 1940 when Germany launched its next offensive.
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3. The German Blitzkrieg in Western Europe (April – June 1940)
After months of little activity, Hitler struck with overwhelming force, quickly defeating multiple countries.
Invasion of Denmark and Norway (April 1940)
Germany launched Operation Weserübung on April 9, invading Denmark and Norway.
Denmark surrendered in a single day.
Norway resisted with British and French support, but Germany secured the country by June 10.
The Fall of France (May – June 1940)
On May 10, 1940, Germany invaded France and the Low Countries (Belgium, Netherlands, Luxembourg) using Blitzkrieg tactics.
The Netherlands fell within five days, Belgium within two weeks.
Germany bypassed the Maginot Line by attacking through the Ardennes Forest, a move that took the Allies by surprise.
The British and French forces were soon overwhelmed.
The Dunkirk Evacuation (May 26 – June 4, 1940)
With German forces advancing rapidly, over 338,000 British and French troops were trapped at Dunkirk.
The British launched Operation Dynamo, using military and civilian ships to evacuate troops across the English Channel.
The operation was a success but left France exposed.
On June 14, 1940, German forces entered Paris, and France officially surrendered on June 22. The country was divided into:
Occupied France (controlled by Germany).
Vichy France (a German-aligned puppet state).
With France defeated, Britain stood alone against Nazi Germany.
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4. The Battle of Britain (July – October 1940)
Hitler aimed to conquer Britain through Operation Sea Lion, but first, he needed to defeat the British Royal Air Force (RAF). This led to the Battle of Britain, an intense air war between Germany's Luftwaffe and the RAF.
Phases of the Battle
1. Luftwaffe targeted airfields and radar stations (July – August 1940).
2. Germany bombed cities in the Blitz (September – October 1940), killing thousands of civilians.
3. RAF fought back with Spitfire and Hurricane fighter planes, aided by radar technology.
Outcome
Britain successfully defended its airspace, forcing Germany to abandon its invasion plans.
The battle was Germany's first major defeat in the war.
Prime Minister Winston Churchill famously declared, "Never in the field of human conflict was so much owed by so many to so few."
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5. The Expansion of the War (1940 – 1941)
Italy Joins the War (June 1940)
Mussolini's Italy declared war on Britain and France, attempting to expand its empire in Africa and the Balkans.
Italian failures in Greece and North Africa forced Germany to intervene.
The Balkan Campaign (April – June 1941)
Germany invaded Yugoslavia and Greece, quickly conquering both.
This delayed Hitler's plans for the Soviet Union but secured the Balkans for the Axis.
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6. The German Invasion of the Soviet Union (June 1941)
On June 22, 1941, Germany launched Operation Barbarossa, the largest military invasion in history.
Over 3 million German troops invaded the Soviet Union along a 1,800-mile front.
Stalin was caught off guard, and Soviet losses were immense.
Key Battles
Siege of Leningrad (1941–1944) – A brutal blockade lasting over 900 days.
Battle of Moscow (1941) – Soviets halted the German advance, helped by the harsh winter.
Despite initial German successes, the invasion would ultimately lead to Germany's downfall.
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7. Japan and the War in the Pacific (1937–1941)
While Germany waged war in Europe, Japan expanded its empire in Asia.
1937 – Japan invaded China, leading to the Second Sino-Japanese War.
1940 – Japan occupied French Indochina.
1941 – Japan signed the Tripartite Pact with Germany and Italy, forming the Axis Powers.
Tensions with the United States
The U.S. imposed economic sanctions on Japan, cutting off oil supplies.
Japan saw this as an act of aggression and planned to attack.
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8. The Attack on Pearl Harbor (December 7, 1941)
On December 7, 1941, Japan launched a surprise attack on the U.S. naval base at Pearl Harbor, Hawaii.
Over 2,400 Americans were killed.
Several battleships and aircraft were destroyed.
U.S. Enters the War
On December 8, 1941, the United States declared war on Japan.
Germany and Italy then declared war on the U.S.
The war was now a truly global conflict.
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Conclusion
The first two years of World War II saw rapid German conquests in Europe, a fierce air battle over Britain, and the expansion of the war into the Soviet Union and the Pacific. With the United States now involved, the war had entered a new and even more intense phase.
In the next chapter, we will explore The Turning Points of the War (1942–1943), including Stalingrad, Midway, and the Allied counteroffensive.