World War II was the largest, most widespread, and deadliest armed conflict in human history. Spanning from 1939 to 1945, it involved over 30 countries across every inhabited continent. More than 100 million military personnel were mobilized from over 70 million persons under arms at its height in 1945. Conservative estimates show over 70 million people perished during the war, including about 27 million soldiers and as many as 50 million civilians caught in the crossfire of battles, genocide, starvation and devastation. No previous military conflict matched World War II's unprecedented scale, cost in human lives, strategic and ideological importance, or profound social and political impacts that reshaped the modern world.
Root Causes and Build Up
The origins of World War II
can be directly traced to the aftermath of World War I and the harsh terms
imposed on Germany by the Treaty of Versailles in 1919. Having helped provoke
the first World War through its plans for aggressive militarism and conquest, a
defeated Germany was forced to accept full responsibility and liability.
Substantial territories were stripped away, including all its overseas
colonies. The German military was severely restricted to just 100,000 troops,
its air force eliminated, and the Rhineland region bordering France completely
demilitarized.
Most damaging were the heavy
economic reparations Germany was required to pay annually to Britain, France,
and other Allied powers for war damages. Combined with the loss of
resource-rich territories and industries, these punitive sanctions crippled
Germany's economy throughout the 1920s as it struggled to rebuild and make
reparation payments. This dire situation created fertile ground for the rise of
Adolf Hitler's Nazi party and its platform of militant German nationalism and
anti-Semitism.
Hitler, a World War I
veteran, skillfully tapped into the public anger, paranoia and resentment of
humiliating terms forced upon Germany at Versailles. His powerful oratory
condemned the treaty's "perpetual bondage" and incredible reparation
burden as an existential injustice perpetrated by its wartime enemies. Hitler
spread a virulent ideology of anti-Semitism, scapegoating Jews and other ethnic
minorities as the root causes of Germany's downfall and economic woes. Promises
to restore Germany's dignity and lay claim to greater "Lebensraum" or
living space for ethnic Germans increasingly resonated.
Rise of Hitler and the Nazi
State
In 1933, Hitler's Nazi party
won a plurality in elections and he was appointed Chancellor of Germany. He
swiftly transformed the once democratic republic into a totalitarian fascist
state and declared himself the supreme Fuhrer. Using emergency powers initially
intended to restore order, Hitler outlawed opposition parties, purged
dissenting voices and established absolute control over the German military,
media, industry, judiciary and all levels of government.
Hitler's heavy
re-militarization program began rearming the nation with modern weapons and
equipment despite the strict Versailles restrictions. His first provocative
move was sending troops to re-occupy the Rhineland demilitarized zone in 1936.
This blatant violation by massed infantry and artillery formations was
surprisingly uncontested by Britain and France, whetting Hitler's appetite for
further destabilizing actions. At the same time, he pulled Germany out of
disarmament talks and allied with the increasingly militaristic fascist regimes
in Italy under Mussolini and Imperial Japan, forming the Axis powers.
In 1938, Hitler pushed the
policy of Anschluss, sending troops to annex neighboring Austria and its
considerable economic assets after a choreographed referendum approved the
takeover. He then turned his sights on occupying the Sudetenland region of Czechoslovakia,
claiming it was needed to protect ethnic Germans living there from persecution.
Concerns of "ethnic Germans" became the standard pretext for
dismantling the young nation.
The Munich Agreement
temporarily averted a full war by allowing Nazi Germany to annex the
Sudetenland. British Prime Minister Neville Chamberlain pursued a disastrous
policy of appeasement, believing this would satisfy Hitler's territorial aims
and prevent a larger conflict from erupting. However, less than a year later in
March 1939, the remainder of Czechoslovakia was brazenly occupied by German
forces in defiant violation of the agreement. Czechoslovakia's industrial
manufacturing capabilities and defensible geographic position controlling
routes into Germany proved too valuable to pass up.
The Nazi-Soviet Alliance
In August 1939, the world
was stunned when Nazi Germany and the Soviet Union signed the
Molotov-Ribbentrop Non-Aggression Pact. This established a tentative alliance
between the totalitarian ideologues of Communism and Fascism, despite their
conflicting national interests and political philosophies that made their
regimes natural adversaries.
The pact contained a secret
protocol dividing territories in Eastern Europe into Soviet and Nazi spheres of
influence. Stalin likely calculated that the agreement would buy time to
continue the Soviet Union's military build-up and industrialization by avoiding
a two-front war with Germany. For Hitler, the pact neutralized the threat of
Soviet opposition as he prepared to pursue lebensraum ("living
space") for the German people in Eastern Europe.
With the Soviet alliance
secured, Hitler's forces were free to strike Poland without fear of a two-front
war in the west against France and Britain as well. The conquest of Poland was
the fuse that ignited World War II in Europe.
Opening Salvos and the
Invasion of Poland
On September 1, 1939, over
1.5 million German troops and 2,500 tanks smashed into Poland from the west in
a tremendous blitzkrieg assault. This innovative offensive used coordinated air
power, artillery, and combined arms of infantry, tanks, and mobile forces to
penetrate enemy defenses rapidly. Despite determined Polish resistance, the
blitzkrieg's speed and concentration of firepower proved overwhelming.
In a shocking coordinated
move, over 600,000 Soviet forces also invaded eastern Poland just over two
weeks later on September 17th in keeping with the secret protocol of the
Molotov-Ribbentrop Pact. Facing this two-front assault, Poland's vastly
outnumbered defenses were rapidly overrun and unable to fall back to more
defensible positions.
Poland's defeat came swiftly
after just over a month of fighting against the Nazis and Soviets. Its
remaining troops surrendered after Germany's capture of Warsaw on September
28th following heavy bombardment and urban warfare that killed over 200,000 civilians.
Over 420,000 Polish troops were captured as prisoners of war during the
campaign. In the end, Poland was brutally carved up and occupied, with Germany
annexing the western regions and the Soviet Union taking over the eastern
territories as a puppet regime.
This blatant violation of
Polish sovereignty and partition of the nation prompted Britain, France,
Australia, and New Zealand to honor their commitments and declare war on
Germany on September 3rd, 1939 - officially marking the start of World War II
in Europe. However, there were no immediate military operations by the Allies
beyond a severely inadequate naval offensive.
The Phony War, Then
Blitzkrieg in the West
After their declarations of
war, Britain and France along with their British Commonwealth allies did little
to actively prosecute the conflict or support Poland in any tangible way for
the next eight months. This was derisively termed the "Phony War" or
"Sitzkrieg" as both sides watched in a defensive stance with only
minor skirmishes along the French-German borders. The reasons for this inaction
remain debated, but likely stemmed from lack of military readiness, Polish
reluctance to allow foreign troop presence, and hopes that Hitler's ambitions
were satiated.
Hitler easily took advantage
of this lull to fortify Germany's western frontiers with the construction of
the Siegfried Line defenses facing France. He also methodically planned for a
bold offensive through the Ardennes Forest and into France to knock out the
Allies quickly before they could be reinforced.
On May 10th, 1940, this
highly mobile and concentrated blitzkrieg assault codenamed Fall Gelb (Case
Yellow) was unleashed. It shocked the Allies with its speed and by bypassing
the vaunted French defenses of the Maginot Line by cutting through the Ardennes,
which was assumed impassable for tanks. Combining Panzer tank formations, Stuka
dive bombers, and waves of infantry, the Germans rapidly pushed across the Low
Countries and into northern France, flanking and isolating many French and
British positions.
The Fall of France
The German blitzkrieg into
France proved unstoppable as the outmaneuvered Allied forces struggled to
establish a coherent defensive line. Within six weeks, the Netherlands, Belgium
and Luxembourg had been overrun and surrendered. British and French armies were
cut off from each other and pushed back to the beaches of northern France in
the culminating Battle of Dunkirk.
In a remarkable evacuation,
the British Expeditionary Force managed to escape annihilation by evacuating
over 338,000 soldiers across the English Channel to Britain between May 26th
and June 4th, 1940. However, they were forced to abandon nearly all their
vehicles, equipment and supplies on the beaches in this tactical defeat.
Lacking reserves and videly
outnumbered, French resistance crumbled rapidly after Dunkirk. A series of
German pincer movements and the complete collapse of French morale led to an
Armistice being signed on June 22nd, 1940 that granted the Nazis full military
occupation over northern France. Only a small unoccupied zone in the south
remained under nominal French control.
The swift fall of France after
less than two months was a devastating blow to the Allies. Germany now
controlled the resource riches of the French empire's colonial territories as
well as most of Western Europe. Only Britain remained defiant, pushing Prime
Minister Winston Churchill to defiantly declare "We shall fight on the
beaches..."
The Battle of Britain
With France conquered,
Hitler turned his ambitions toward invading and subduing Britain to eliminate
their ability to continue the war effort. He hoped to complement the
Luftwaffe's air bombardment with an amphibious and airborne invasion once the
Royal Air Force had been defeated and British cities devastated.
From July 1940 through May
1941, the two air forces engaged in the prolonged Battle of Britain campaign
that proved pivotal. The first phase targeted British shipping and coastal
regions, while the second saw the Blitz of devastating bombing raids on cities
like London, Coventry and others to break British morale and industrial
capabilities.
Despite taking heavy losses,
the undermanned RAF Fighter Command managed to inflict unsustainable aircraft
losses on the Luftwaffe through superior radar, tactics and the heroics of
pilots like those in the Royal Canadian Air Force squadrons. By September 1940,
Hitler reluctantly postponed any planned invasion of Britain due to heavy
German bomber losses and British air superiority in the critical southeast
region.
The Battle of Britain marked
the first major Allied victory over the Nazi war machine and the start of the
turning of the tide in the air war. It proved to be one of the most crucial
campaigns of the war in denying Hitler a foothold in the British Isles from
which to launch his intended invasion of the Soviet Union.
Operation Barbarossa and the
Eastern Front
With Britain defiant, Hitler
set his sights on the conquest of the Soviet Union in the east as part of his
desires for Lebensraum or "living space" for the German people.
Launching the massive surprise invasion codenamed Operation Barbarossa on June
22nd, 1941, over 3.8 million Axis troops poured across Soviet borders along an
1800-mile frontline from the Barents to the Black Sea. This was the largest
military operation in human history up to that point.
Despite their surprise
attack and employment of superior blitzkrieg tactics, logistics issues and the
resilience of Soviet resistance prevented the complete Axis victory that the
Nazis had anticipated within a few months. While huge swaths of Soviet territory
were captured and major cities like Minsk, Smolensk and Kiev occupied, the Red
Army avoided envelopment and total destruction by trading space for time.
Two major Nazi offensives
that summer of 1941 sought the capture of the cities of Leningrad and Moscow to
strike at the heart of the Soviet Union. The prolonged siege and bombardment of
Leningrad lasted nearly 900 days and cost over a million Soviet military and
civilian lives through combat and starvation. However, the city never fell to
Axis control.
Outside Moscow, the battle
proved even more pivotal as two million Soviet troops overwhelmed and defeated
the initial 75-mile advance by three German Army Groups in the largest battle
of the entire war. General Georgy Zhukov's brilliant counteroffensive in
December routed the Germans from the outskirts of Moscow as the harsh Russian
winter set in, inflicting over a million casualties in bitter fighting and
forcing the Nazis into full retreat.
The failure to capture Moscow and secure air superiority over the Soviet capital proved disastrous for the Germans, as their blitzkrieg offensive stalled just 15 miles from the Kremlin. Coupled with threatening Soviet counterattacks, Hitler was forced