Exhaustive Notes on the Second World War: German Expansion, Italian Parallel War, and the Eastern Front (1939-1942)

The German Blitzkrieg and the Rapid Advance (1939-1940)

The initial phase of the Second World War was characterized by a series of swift and overwhelming German victories facilitated by the strategy of "Blitzkrieg" (lightning war). This military doctrine integrated speed, surprise, and the coordinated use of armored divisions known as "panzer," the air force (Luftwaffe), and motorized infantry. This approach shifted the conflict from a static war of position back to a war of movement, as panzer divisions were capable of bypassing traditional defensive trenches.

The conflict formally commenced on September $1$, $1939$, when Nazi Germany, under the leadership of Adolf Hitler, invaded Poland without a formal declaration of war. Two days later, on September $3$, following their mutual assistance pact with Poland, France and Great Britain declared war on Germany, marking the start of the global conflict.

The First Phase: The Invasion and Fall of Poland

Poland was defeated in less than a month. By September $18$, $1939$, German troops had occupied the majority of the country, and the capital, Warsaw, resisted until September $27$. Simultaneously, the eastern portion of Poland was invaded by the Soviet Union. This dual occupation was conducted according to the Ribbentrop-Molotov Pact, a secret agreement between Hitler and Stalin that outlined the partitioning of Poland.

Following the Polish campaign, the Western Front experienced several months of relative military inactivity despite the formal declarations of war. This period was dubbed "drôle de guerre" ("phoney war" or "strange war") by the French. It was an era where conflict existed primarily on paper, with neither side launching major offensives while both prepared for eventual direct combat.

The Second Phase: Conquest of Northern Europe and the Western Offensive

In April $1940$, the second phase of German expansion began with the rapid occupation of Denmark and Norway. These nations were strategically vital for controlling the North Sea and securing Swedish iron ore resources, which were indispensable for the German war industry.

On May $10$, $1940$, Hitler launched a large-scale offensive against Western Europe. German forces invaded the neutral countries of Holland, Belgium, and Luxembourg to bypass the French Maginot Line. This fortification system, over $400\,km$ long, was built directly on the German border and was rendered useless when the Germans advanced through the Ardennes forest. The French military had wrongly deemed the hilly Ardennes terrain impassable, yet German armored divisions broke through here, overwhelming the Allied forces.

Operation Dynamo and the Fall of France

The offensive reached its peak at Dunkerque (Dunkirk), where hundreds of thousands of Anglo-French soldiers were encircled on the coast of the English Channel. Between May $24$ and June $3$, $1940$, an exceptional naval operation known as "Operation Dynamo" successfully evacuated approximately $340,000$ soldiers—primarily British, but also French and Belgian—who found refuge in England. This successful rescue was essential for Britain's continued participation in the war.

On June $14$, $1940$, German troops entered Paris. France signed an armistice on June $22$. The country was subsequently divided into two zones: the northern and central-northern regions were occupied by Germany, while the southern part, with its capital at Vichy, remained formally independent under a collaborationist government led by Marshal Philippe Pétain. Pétain’s right-wing administration actively collaborated with the German occupiers.

However, not all French citizens accepted the surrender. On June $18$, $1940$, General Charles De Gaulle broadcast an appeal from Radio London, urging the "Free French" to resist and continue the fight against Nazism. This created two opposing internal fronts: the collaborators, who accepted Nazi rule out of opportunism or conviction, and the resistance, who opposed the dictatorship through sabotage, clandestine movements, propaganda, and guerrilla warfare.

The Battle of Britain and Technological Turning Points

In Great Britain, the government of Neville Chamberlain fell and was replaced by Winston Churchill, who had long advocated for the necessity of fighting Hitler to protect the liberal West. Following France's surrender, Britain stood alone against Germany. Hitler launched a massive aerial offensive on July $10$, $1940$, known as the Battle of Britain, the first major campaign in history fought entirely in the air.

Hitler's objective was to achieve air superiority as a prerequisite for a sea-based invasion that never materialized. He ordered "The Blitz," massive carpet bombings of major English cities, particularly London. A low point occurred in November $1940$ with the total destruction of Coventry, a vital industrial hub for Warwickshire's coal and war production. The Nazis coined the term "coventrizzare" (to coventrize) to signify the systematic destruction of an enemy urban center.

Despite heavy losses, Britain resisted through the determination of the populace, Churchill’s rhetoric, and the innovative use of radar technology, which allowed for the interception of German bombers. By late November $1940$, having lost approximately $1733$ aircraft, Hitler suspended the offensive. This marked the Third Reich's first major defeat. It demonstrated that Blitzkrieg was ineffective against a technologically advanced island nation prepared for a war of attrition—a type of conflict Germany could not sustain due to shortages of raw materials such as gasoline, rubber, lead, copper, and coal.

The Italian Entry and the "Parallel War" Strategy

On June $10$, $1940$, as France was nearing collapse, Italy entered the war by declaring war on France and Great Britain. Benito Mussolini had initially declared Italy "non-belligerent" because he had not been informed of the Polish invasion by Hitler. However, he feared that a solo German victory would exclude Italy from the division of territories. Mussolini famously stated, "I need a handful of dead so that I can sit at the bargaining table," believing the war was almost over.

Despite the "Vincere e vinceremo!" ("To win and we shall win!") rhetoric, the Italian military was severely underprepared. Weapons were dating back to WWI, armored units were ineffective, and the air force was obsolete. Italy had been drained by the wars in Ethiopia and Spain. Mussolini proposed a "parallel war," aiming to expand Italian influence in the Mediterranean and the Balkans autonomously from Germany.

Failures of the Italian Military Fronts

On the Alpine front in June $1940$, Italy launched a marginal offensive against a collapsing France, advancing only $6\,km$ and capturing Mentone. The international community labeled this an opportunistic "stab in the back" (pugnalata alla schiena).

In North Africa, General Rodolfo Graziani ordered an advance into Egypt on September $13$, $1940$, reaching Sidi Barrani ($70\,km$ past the border). However, a British counter-offensive launched on February $6$, $1941$, under General Wavell, crushed the Italian forces. Italy lost the entire Cirenaica region and $130,000$ men were taken prisoner. Germany had to intervene by sending the Afrikakorps under General Rommel (the "Desert Fox") to save the front. Eventually, these forces were defeated by Bernard Law Montgomery at the Battle of El-Alamein.

In East Africa, the Italian colonies of Ethiopia, Eritrea, and Somalia were isolated and conquered by the Allies. Emperor Haile Selassie returned to Addis Abeba on May $5$, $1941$, ending the five-year Italian colonial empire. In the Balkans, Italy’s October $1940$ attack on Greece was a disaster; Greek forces counter-attacked and occupied part of Albania. Germany intervened in April $1941$, invading both Yugoslavia and Greece. These territories were divided: Croatia became a puppet state led by Ante Pavelić and the Ustascia, while Serbia and Albania were placed under collaborationist regimes. Resistance movements emerged here, led by the monarchist Draža Mihajlović and the communist Josip Broz Tito.

Operation Barbarossa and the War in the East (1941-1942)

On June $22$, $1941$, Germany launched Operation Barbarossa, the invasion of the Soviet Union. This was the largest military operation in history, involving over $3$ million soldiers, $10,000$ tanks, and $3,000$ aircraft. To Hitler, the USSR was the ultimate ideological enemy. This was not just a military campaign but a war of extermination and colonization aimed at securing "Lebensraum" (living space).

Nazi policy in the East was brutal: Soviet political commissars were executed, millions of prisoners were left to die in camps, and entire villages were burned. The "Mobile Shoah" began with mass shootings of Jews before the creation of the death camps. Initially, the Red Army lost territory west of the Moscow-Leningrad-Rostov line, losing $3$ million soldiers and $3,000$ tanks in three months. However, the vastness of the territory, supply difficulties, and the Russian winter stalled the advance.

By autumn $1941$, Stalin reorganized the defense. The Red Army stopped the Germans at the gates of Moscow, and partisan groups began sabotaging German supply lines. By early $1942$, the Blitzkrieg in the East had failed, and the conflict transitioned into a long, brutal war of position.

The Nazi "New European Order" and the Resistance

Hitler’s vision for a "New Order" was a hierarchical pyramid:

1. The Greater Germany as the dominant power.

2. Allied countries (Italy, Hungary, Romania, Bulgaria).

3. Satellite states (Vichy France, Slovakia).

4. Conquered territories treated as colonies for exploitation.

Resistance movements rose across Europe in response to this oppression. These groups engaged in armed action, sabotage of railways and factories, clandestine press, intelligence gathering for the Allies, and hiding persecuted individuals. In the USSR, the Red Army worked with civilian partisans; in France, Yugoslavia, Greece, Poland, Italy, and the Netherlands, organizations were formed by citizens, often coordinated by anti-fascist parties.

Historian Claudio Pavone identifies three dimensions of the Resistance:

• Patriotic War: To liberate the nation from foreign occupiers.

• Civil War: Between citizens of the same country with opposing ideologies.

• Class War: Particularly for communist/socialist partisans who sought a social revolution and the end of capitalism.

These movements were vital to Allied success as they tied down German troops and disrupted communications, later forming the foundation for postwar democratic renewals and new national constitutions.