Six Weeks to Defeat The Fall of France, 1940: World War 2

By Ivo Vichev

In May 1940, the French Army was widely seen as the strongest land force in Europe. By mid-June, France had fallen, its government in flight, its soldiers marching into captivity. Between those dates lies one of the most misunderstood campaigns of the Second World War.

Told through the eyes of Lieutenant Pierre Dubois, a fortress engineer at the massive Maginot Line position of Fort Hackenberg, this book follows the Battle of France from the illusion of security to the shock of defeat – and into the prison camps where officers have nothing left but time to ask what went wrong.

Inside the fort's concrete galleries, Dubois and his men begin the campaign convinced that technology, planning and firepower have made France impregnable. As German forces break through at Sedan, race to the Channel and encircle entire armies, that confidence shatters. Orders arrive late or not at all. Communications fail. Refugee columns clog the roads. Air attack becomes a constant, terrifying presence.

In a transit compound attached to Stalag IV-D in Saxony, Dubois joins officers from armoured divisions, staff headquarters and the Dunkirk perimeter. Around a rough table of Red Cross crates, they start to piece together the larger story of France's defeat.

The book weaves front-line narrative with clear, structured analysis, showing how tactical shocks and deep structural flaws combined to bring down a great power at unprecedented speed:

• Doctrine built for 1918, not 1940: a defensive "Maginot mentality" facing an enemy who treated fortifications as obstacles to go around, not walls to assault.
• Blitzkrieg as a system: tanks, aircraft, artillery and radio used together to create tempo, shock and constant uncertainty.
• Leadership and command failure: cautious headquarters, rigid chains of command and senior officers chosen for bureaucracy rather than battlefield imagination.
• Politics and industry: revolving-door governments, budget cuts and stop–start rearmament versus a regime that aligned strategy, economy and propaganda to a single goal.
• Intelligence that counted weapons but missed ideas: German doctrine and operational thinking evolving faster than French analysts could accept.
• Air power and morale: dive-bombers used as flying artillery, a scattered French air force, and the psychological impact of realising that the sky itself now belonged to the enemy.
• Alliance failure: French, British and Belgian forces fighting side by side but not truly together, with incompatible doctrines, equipment and priorities.

By the time Dubois closes his makeshift journal in the dim light of the camp gymnasium, the military verdict is clear: France did not fall because its soldiers lacked courage, but because its institutions, doctrine and leadership proved unable to match a new form of war.

The Battle of France lasted six weeks. Its consequences – occupation, collaboration, resistance and a transformed balance of power in Europe – shaped the rest of the Second World War and the world that followed. This book shows how and why it happened.

• Language: English
• Publisher: Ivo Vichev
• Release date: Dec 11, 2025
• ISBN: 9798232586973

Ivo Vichev

I was born in Varna, Bulgaria, on the edge of the Black Sea – a place where history is never really "past". Growing up between old empires and new borders, I was surrounded by stories of wars, occupations, disappearances and sudden changes of flag. Later I moved to Warsaw, Poland, where I studied history and public relations at the Polish Academy of Sciences (PAN). Warsaw is a city built on ruins and memories, and it forced me to ask one question over and over again: Why is so much of our most important history told in the most boring way possible? From dry facts to living stories Like every history student, I spent endless hours buried in heavy academic books – dates, treaties, footnotes stacked on footnotes. I respected the work, but I often felt like the life had been drained out of the events themselves. That changed when I discovered Ryszard Kapuściński. His books had that rare tone I'd been searching for: history and politics told through people, scenes and atmosphere. It was factual, but it breathed. From that moment I knew what I wanted to do: take serious history and tell it with the clarity and tension of a documentary – so future generations don't have to suffer through dead, lifeless books to understand the past. What I write about My books focus on the places where power is most visible – and most hidden: Wars and battles Espionage and cyber conflict Country histories Some books are big, sweeping national histories. Others zoom in on a single battle, uprising or covert operation. All of them try to answer the same question: What really happened here, and what does it mean for the people who had to live through it? How I tell history If you read my books, you can expect narrative, scene-by-scene storytelling – not just lists of dates. Serious research from archives, memoirs, official reports and investigative journalism. Clear explanations of complex events like cyberattacks and proxy wars. And a refusal to simplify messy, uncomfortable truths. I don't write official history. I don't write propaganda. I write stories that are honest, human and readable – the kind of books I was always looking for as a student and rarely found. If you care about how we got from trenches and partitions to cyberwar and drone strikes – and you don't want to fall asleep over another textbook – I wrote these books for you.

Book preview

Six Weeks to Defeat

The Fall of France, 1940

Ivo Vichev

© 2025 Ivo Vichev

All rights reserved.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopying, recording, or otherwise—without the prior written permission of the author, except in the case of brief quotations used in reviews, critical articles, or scholarly work.

This book is a work of non-fiction. Every effort has been made to ensure the accuracy of dates, names, and events. Any errors that remain are the author’s alone.

First edition, 2025

Table of Contents

Chapter 1: The Calm Before the Storm

Chapter 2: The German Plan Unfolds

Chapter 3: The Sickle Cut

Chapter 4: The Race to the Sea

Chapter 5: The Cauldron Forms

Chapter 6: Miracle at Dunkirk

Chapter 7: The Second Phase

Chapter 8: The End Approaches

Chapter 9: The Armistice

Chapter 10: Analysis and Consequences

Chapter 1: The Calm Before the Storm

Lieutenant Pierre Dubois stepped from the electric-lit galleries of Fort Hackenberg into the February dawn of 1940, adjusting his collar against the Lorraine cold. At twenty-six, the son of a Marseille dockworker had found his calling in the geometrical precision of fortress warfare—ranges, angles of fire, interlocking defensive zones that could be calculated and perfected like a problem in trigonometry. From Casemate Sud-Est, he surveyed the frost-covered fields stretching toward Germany, where the concrete bunkers of the Siegfried Line sat barely visible through morning mist.

Five months had passed since general mobilisation. Five months of what Parisian newspapers called the Drôle de guerre—the strange war where armies faced each other across fortified lines but rarely fired a shot. Dubois had grown to love the routine: morning inspections of the massive 75mm guns, equipment checks in the underground galleries, evening patrols along the perimeter. The Maginot Line felt like home now, a concrete city beneath the earth where more than a thousand men lived in electric-lit comfort, protected by walls that could withstand the heaviest artillery.

Another quiet day, Sergeant Moreau observed as they shared morning coffee in the fortress's underground café. The grizzled veteran of Verdun stirred his cup thoughtfully, eyes crinkling with the confidence of a man who had seen the Germans come before. Let them study our positions all they want. When they finally work up the courage to attack, they'll find walls they cannot break.

But something had changed in recent weeks. During his evening patrols, Dubois noticed increased activity across the frontier—lights moving behind the Siegfried Line bunkers, more frequent reconnaissance flights, patrols that seemed to be mapping French positions with systematic precision. He made careful notes in his leather-bound logbook but saw no reason for alarm. This was exactly what the Maginot Line had been built for.

The Maginot Line had cost nearly seven billion francs to build, and Hackenberg alone—with its garrison of more than a thousand men—embodied a decade of French military engineering. Its 75mm turrets could throw shells more than twelve kilometres into German territory, knitting the frontier into interlocking fields of fire. Every casemate, every underground railway, every defensive position had been designed by engineers who remembered the slaughter of 1914–1918. Never again would German armies pour through unprepared defences into the heart of France.

Far from the quiet galleries of Hackenberg, General Erich von Manstein studied maps with the intensity of a chess master contemplating a killing combination. Tall, austere, with the kind of intellectual arrogance that made him few friends among fellow generals, Manstein had recently been removed from his post as chief of staff of Army Group A and promoted away to command XXXVIII Army Corps in Stettin—essentially a polite exile for his persistent advocacy of unorthodox ideas.

Through seven separate memoranda during the winter months, Manstein had argued that Allied defensive preparations made the obvious approach through Belgium predictable and therefore vulnerable. His alternative was breathtaking in its audacity: concentrate seven panzer divisions for a massive thrust through the supposedly impassable Ardennes Forest, hitting the weakest sector of French defences while Allied armies rushed north to meet the expected attack in Belgium.

Manstein warned that the Allies expected Germany to repeat the 1914 invasion through Belgium—and argued that this expectation itself was Germany's greatest advantage. It was military misdirection on a continental scale: get the audience looking at your right hand while your left hand performs the real trick.

The strategic insight had found its perfect tactical partner in General Heinz Guderian, the Reich's leading advocate of armoured warfare. A former signals officer who understood how radio communications could coordinate mechanised units, Guderian spent the winter training his XIX Army Corps in breakthrough techniques that made such audacious plans possible. His tank crews practised river crossings at speed, exploitation manoeuvres, and the close coordination between tanks, motorised infantry, and dive-bombers that German theorists believed could revolutionise warfare itself. Every exercise emphasised one revolutionary principle: speed and concentration could overcome defensive superiority, but only if applied before defenders could organise an effective response.

Back at Fort Hackenberg, Lieutenant Dubois completed his afternoon inspection of the fortress's main armament, the 75mm guns gleaming with protective oil in the artificial light. Each weapon could reach targets more than ten kilometres into German territory, creating interlocking fields of death that any attacking force would have to cross. As he climbed back down into the underground city, the lieutenant felt the deep satisfaction of careful calculation made concrete and steel.

In the ornate conference room of the Château de Vincennes, however, his confidence was being systematically undermined by the very man charged with defending France.

General Maurice Gamelin looked nothing like a military commander. At sixty-eight, the diminutive former professor resembled an ageing clerk more than the generalissimo of French forces. His small office was cluttered with theoretical studies and historical analyses, connected to the outside world by a single telephone line that often failed to function. Subordinates joked—quietly—that their commander-in-chief seemed to exist in a world of abstract principles rather than military realities.

When Gamelin briefed Premier Édouard Daladier on 12 February 1940, his presentation combined statistical confidence with strategic reassurance. Time works decisively in our favour, the general explained, gesturing at charts showing Allied advantages. German industrial capacity remains constrained while our production increases monthly. Every week of delay strengthens our position.

French intelligence supported this optimism with precise calculations. Allied armour strength, counting French, British and Belgian tanks, approached four thousand vehicles. German stocks numbered about 3,300 to 3,400, most of them light tanks. The numbers seemed to prove French superiority, yet they reflected assumptions about tank employment that German planners were systematically abandoning.

Gamelin's Plan D called for Allied forces to advance into Belgium the moment Germany attacked, establishing defensive positions along the Dyle River while the Maginot Line anchored the southern front. It was an intricate ballet requiring split-second timing under combat conditions—complexity that would prove fatal when the test came.

During his evening patrol on 28 February, Lieutenant Dubois noticed systematic activity replacing routine maintenance work across the frontier. Lights moved with purpose behind the Siegfried Line bunkers, and the sound of mechanised transport carried clearly in the cold night air. He made careful notes but felt no anxiety. If anything, increased German activity proved the Maginot Line's deterrent effect.

The lieutenant's confidence would have been shaken had he known that German preparations aimed in an entirely different direction. General Franz Halder, the German Chief of Staff, had spent months studying the lessons of Poland with conclusions that would have horrified French commanders.

In his war diary entry of 27 January