The silent start to World War II: How the ‘Phoney War’ unfolded

In the early hours of September 1, 1939, Germany unleashed its forces on Poland as waves of Luftwaffe bombers darkened the sky, and the advance of the Wehrmacht on land shattered Poland’s defenses.

This was known as 'Blitzkrieg': a tactic of swift, overwhelming attacks that were designed to throw enemy militaries into disarray.

Germany’s invasion was a direct violation of both the Kellogg-Briand Pact (1928) and the German-Polish Non-Aggression Pact (1934), which had both promised that Poland would never be attacked by Germany.

Then, the situation for Poland became worse on September 17, when Soviet troops also invaded under the secret terms of the Molotov-Ribbentrop Pact.

After three weeks of relentless bombing and artillery shelling, Poland's capital of Warsaw ultimately surrendered to German forces on September 27, 1939.

The Polish government had already evacuated to Britain by this stage, and within days, the country was fully divided between Nazi Germany and the Soviet Union.

In the days that followed, Europe stood on the brink of total war. Britain and France had signed treaties promising to defend Poland’s sovereignty, and on September 3, 1939, both nations had followed through and declared war on Germany.

While public sentiment in these countries overwhelming supported immediate action, there was no confrontation on the Western Front.

While French troops did move to the German border and conducted a limited offensive, known as the Saar Offensive from September 7–16, they only advanced a few miles into Germany before halting.

Yet, for weeks, no further significant battles occurred. 

Instead, British and French leaders hesitated to launch an immediate offensive against Germany.

This was because they had watched the rapid devastation in Poland and feared that their own armies were not yet ready to face the same aggressive tactics.

The devastating success of Blitzkrieg raised serious concerns about their ability to defend their territories, let alone invade Germany itself.

Military planners wanted more time to prepare for an inevitable confrontation.  

In France, political and military leaders remained deeply scarred by the devastating losses of World War I.

So, the French government, under Premier Édouard Daladier, adopted a defensive strategy.

They chose to trust in the strength of the Maginot Line, a series of fortified with bunkers, underground barracks, artillery emplacements, and anti-tank obstacles that stretched for nearly 280 miles (about 450 km) along France's shared border with Germany.

Over the last decade, French engineers had designed it to withstand heavy bombardments, with concrete walls up to 11 feet thick in some places.

The line's main strongholds incorporated the pre-war strong points at Verdun and Metz, which included thousands of men and heavy artillery guns.

As a result, French military leadership believed this imposing structure would protect their nation from a direct German assault. 

In addition, the government also relied heavily on propaganda to maintain public confidence.

The French government used the term 'la drôle de guerre' (the funny war) to describe the unusual period of inactivity, while French newspapers frequently reported on military preparations, which gave the impression that the nation was biding its time wisely. 

Meanwhile, British leaders faced their own challenges in the opening months of the war.

They hoped that economic warfare, in the form of naval blockades and sanctions, would weaken Germany over time, and could eventually force Hitler into a vulnerable position.

As a result, Britain focused on securing its naval supremacy in the early stages of the war.

In addition, Britain focused much of its preparations on bolstering its air.

In 1939, the British Royal Air Force (RAF) had begun expanding its Fighter Command.

By mid-1940, Britain would have nearly 600 frontline fighter aircraft, including the Supermarine Spitfire and Hawker Hurricane, stationed to protect against potential German air raids.

Additionally, military planners, including Winston Churchill, prioritized strengthening radar installations along the coast.

This was a cutting edge technology that, it was hoped, would give Britain an advantage in detecting incoming enemy planes. 

As France continued to rely heavily on its Maginot Line, the British Expeditionary Force (BEF) began deploying across the Channel on September 30, led by General Lord Gort.

By early 1940, over 150,000 British soldiers were stationed in defensive positions along the Franco-Belgian border.

However, their positioning largely mirrored France’s defensive posture. 

Confident after the quick conquest of Poland, Hitler saw the Phoney War as an opportunity to solidify control over newly occupied territories.

He was not concerned by Britain and France’s inactivity. Instead, his political strategy focused on the preparation for his next major offensive by intensifying industrial production and reorganizing its military forces.

Hitler and his military advisors, including General Gerd von Rundstedt and Field Marshal Walther von Brauchitsch, began planning the invasion of France and the Low Countries.

Joseph Goebbels aimed to reassure the German public that the war was under control, and the temporary pause was portrayed as a sign of Germany’s growing strength.

However, German military preparations centered on the Siegfried Line, which was also known to the Germans as the Westwall.

It was a series of defensive fortifications built opposite the Maginot Line, stretching over 390 miles from the Swiss border to the Netherlands.

By the start of 1940, the line had grown to include over 18,000 bunkers, pillboxes, and tank traps.

However, Siegfried Line was not fully completed by this stage, and many bunkers were still unfinished.

In fact, the German forces relied on natural obstacles and mobile defenses rather than static fortifications, as they were expected to slow any Allied advance and protect Germany’s western frontier.

Despite this, Hitler never intended to rely solely on the Siegfried Line, as he was already planning a more aggressive strategy. 

In early 1940, he assembled more than 2,500 tanks and 1,200 aircraft for the coming offensive: a number that far exceeded those of his opponents.

To achieve these remarkable figures, German factories had been working around the clock to ensure the Wehrmacht had the equipment and supplies needed.

While there were no major land battles during the opening months of the Phoney War, there were a number of important, if only small, naval and aerial skirmishes.

For example, on September 3, 1939, just hours after Britain declared war, the German submarine U-30 sank the British passenger liner SS Athenia, as it mistook if for a miliary vessel.

While it only resulted in the deaths of 112 civilians, it was a violation of international law regarding the targetting of civilian vessels.

Britain responded by implementing its naval blockade against Germany, which was aimed at cutting off supplies and crippling the German economy. 

Regardless, German U-boats continued to harass Allied shipping convoys across the Atlantic.

Then, on September 17, 1939, U-29 torpedoed the British aircraft carrier HMS Courageous, sinking it with the loss of 519 crew members.

The British Admiralty responded by implementing a convoy system similar to those used in WWI, to protect merchant ships by grouping them together under the escort of warships.

By early 1940, this was relatively successful, as Britain sunk several U-boats, including U-27, U-39, and U-40.

While this reduced Allied losses, it did not eliminate the danger entirely, as U-boats, operating in wolfpacks, continued to sink Allied vessels at a disturbing rate.

Then, on the 13th of December 1939, the Battle of the River Plate provided one of the most dramatic naval engagements of the Phoney War.

The German pocket battleship Admiral Graf Spee had been raiding Allied merchant ships and was finally cornered off the coast of Uruguay by British warships HMS Ajax, HMS Achilles, and HMS Exeter.

After a brief but intense exchange of fire, Graf Spee sought refuge in the neutral port of Montevideo.

However, under pressure from British intelligence and believing he faced a superior force, Captain Hans Langsdorff scuttled the ship on December 17 rather than face certain defeat. 

Meanwhile, in the air, on September 4, 1939, just one day after Britain declared war, the Royal Air Force launched its first bombing raid against German naval targets in Wilhelmshaven. However, the attack inflicted little damage, and several British bombers were lost.

Then, the first bombing of the British mainland occurred on October 16, 1939, when a German Heinkel He 111 bomber attacked the naval base at Scapa Flow in Scotland. Once more, this raid caused limited damage, but it did kill one civilian.

The Royal Air Force focused primarily on reconnaissance flights over Germany, gathering intelligence on troop movements and industrial targets.

These missions were risky, as Luftwaffe fighters often intercepted British planes. 

In late November 1939, the Soviet Union launched an invasion of Finland, as Stalin wanted to secure its northwestern frontier.

Stalin’s government had demanded territorial concessions from Finland, which the Finnish government refused.

Soviet forces vastly outnumbered the Finnish defenders and were expected to achieve a quick victory.

However, the Finns, under the leadership of Marshal Carl Gustaf Emil Mannerheim, mounted a fierce and surprising resistance.

Thanks to their knowledge of the harsh terrain and winter conditions, the Finnish army inflicted heavy casualties on the Soviet invaders. 

In addition, Finland received volunteer fighters from countries including Sweden, Norway, Denmark, and even Britain and France.

In fact, the Swedish Volunteer Corps alone sent over 8,000 men to aid Finland against the Soviet invasion.

By the end of March 1940, the Soviet forces had suffered over 126,000 casualties, compared to the Finnish losses of approximately 25,000.

Despite their overwhelming numbers, the Soviet troops were ill-prepared for Finland’s frigid winter and dense forests, which made traditional military tactics ineffective.

This became known as the 'Winter War', and the one-sided casualty rates raised questions about the strength of the Soviet Union's military. 

There were ongoing discussions in Britain and France in the early months of 1940 about whether to send a full expeditionary force to Finland .

This possibility worried Hitler, who feared that Allied forces might establish a foothold in Scandinavia, which would threaten his own strategic plans.

However, in March 1940, the Winter War came to an end with the signing of the Moscow Peace Treaty.

As part of the negotiations, Finland was forced to cede approximately 11% of its territory to the Soviet Union, including the strategic Karelian Isthmus.

Although Finland lost significant land, it preserved its independence, which was a remarkable achievement considering the odds. 

Almost a month later, in April 1940, the period of inactivity known as the Phoney War came to an abrupt and decisive end with the German invasion of Denmark and Norway.

It began on the morning of April 9, when Germany launched Operation Weserübung: a coordinated assault aimed at securing control of Scandinavia.

In a shock to everyone, Denmark fell to German forces within six hours, as its small military was unable to resist the overwhelming speed and coordination of German troops.

Their king, Christian X and his government, chose to surrender quickly to avoid catastrophic civilian casualties.

This made Denmark one of the fastest conquests of World War II.

The German army swiftly occupied the country, which was strategically important for maintaining communication lines to Norway.

Meanwhile, the invasion of Norway proved more complex, as German forces faced determined resistance from Norwegian troops and naval forces.

German paratroopers and warships targeted key coastal cities, including Oslo, Trondheim, and Narvik, where German control would secure access to Sweden’s valuable iron ore shipments.

The British and French scrambled to intervene. British warships engaged German vessels in several naval battles, including the sinking of the Königsberg, a German cruiser, on April 10.

However, despite these efforts, the Allies struggled to halt the rapid German advance. 

By mid-April, German forces had consolidated their hold on southern Norway, and the situation for the Allies became increasingly dire.

British and French troops, who had landed in northern Norway to support Norwegian forces, had initially won a series of early battles, including the First Battle of Narvik (April 10-13, 1940).

This briefly gave the Allies hope of turning the tide. However, logistical difficulties and superior German air power led to their eventual withdrawal.

Then, on June 10, 1940, Norway’s government went into exile and the country formally surrendered.

The fall of Norway provided Germany with crucial naval and air bases from which they could control the North Sea and disrupt Allied shipping routes. 

During the months of the Phoney War, the Allies frequently missed several crucial opportunities to disrupt Germany’s preparations for the invasion of Western Europe.

British and French forces remained behind their defensive lines, hesitant to launch an offensive, prefererring to gather intelligence and strengthen its forces.

As a result, when the Germans launched their surprise assault on France in May 1940, they faced an Allied military that was defensive and reactive rather than prepared for a fast, mobile enemy.