The Plan That Broke the World

The “Schlieffen Plan” and World War I

William D. O'Neil

As July turned to August in 1914, all the Great Powers of Europe mobilized their armies and marched to war with one another. It would take more than 50 months for peace to return, and the better part of a century to heal many of the wounds.

Germany acted only near the end of a chain of actions by other nations, but German troops moved first and set the pattern for the war. They smashed through neutral Belgium before thrusting deeply into France, coming close to knocking France out of the war, and soon were making huge inroads in Russia as well. It was a remarkable performance for an army outnumbered by its foes. Yet four years later the German Empire was swept away, its army a shell, its people starving, its government in chaos.

(For much more detail on the German plan and its fate see The Schlieffen Plan.)

How did the leaders of Imperial Germany come to make the decisions that committed their nation to an all-or-nothing war based on a highly risky strategy?

This book explores the background of the decisions, what those who made them knew and thought, what they failed to look at and why. It explains the Prussian Great General Staff (Großer Generalstab) and the part it played in planning and preparing for war. It follows the action of August and the first part of September 1914 to show where they went wrong and how other options could have achieved Germany’s aims with far lower risk and cost. These options were realistically available and the book probes why the nation’s leaders failed to consider or rejected them.

The German leaders in 1914 weren’t Hitler. They valued security over conquest and didn’t go to war to expand their empire. They weren't the first to light the fuze that led to war. They thought and acted as leaders very often do. We can understand them in terms of patterns we see all around us, patterns we even see in ourselves. Their decisions had results that were uniquely catastrophic, but the way they were reached was quite ordinary.

The Plan That Broke the World explains it all briefly and crisply, in non-technical terms, drawing on the latest research. There are dozens of images, many unique to this book, to illustrate specific aspects of the story. Four charts and eleven high-quality maps, all but one drawn especially for this book, present complex information in forms that are immediately understandable. There’s no other book like it.

The Plan That Broke the World is a case study in the What Were They Thinking? series.

Links to world-wide sales sites below


“Will O'Neil has written a truly superb account of the events that led to the German defeat in World War I. His superb research, analysis, and insights make this work a must read for all those who study history or wish to learn from the critical mistakes of the past. This is the best writing on this subject I have read.”

General Anthony C. Zinni, USMC (Retired)

Unique perspective and analytic skill bring understanding of the complex contexts surrounding the German Empire’s French offensive in August 1914.  Accounts for the contentious scholarship in the field that surrounds the notorious “Schlieffen Plan” while at the same time bringing an appreciation of both the limitations of the plan as well as its possibilities, and how these led to the stalemate on the Western Front and derailed Western Civilization in the second decade of the 20th Century.  A superb read, even for those who think themselves already well-versed in this topic.

— John T. Kuehn, Ph.D., William A. Stofft Professor
U.S. Army Command and General Staff College, Fort Leavenworth, KS
Author: Agents of Innovation

“A very readable and sometimes eye-opening analysis. It’s a good read and I recommend it highly.”

Vincent P. O’Hara, author of Black Phoenix, In Passage Perilous,
and other books of military history

“Easy-reading style and unique focus on campaign planning and decision-making will appeal to generalists and specialists alike.”

Marc Romanych, author of 42 cm “Big Bertha” and German Siege Artillery of World War I

Second Edition

The second edition is now in print, differing from the first only in the Introduction (especially pages 6-7). Click on the link for a PDF copy of the revised Introduction.

Where to buy The Plan That Broke the World

The Plan That Broke the World is available as an electronic book in Amazon Kindle form or as a high-quality softbound print-on-demand book. The content is essentially identical.

In the United States:

Amazon Kindle edition

Soft-bound edition

In the United Kingdom:

Amazon Kindle edition

Soft-bound edition

In Australia:

Amazon Kindle edition

Soft-bound edition not available from Amazon Australia

In Canada:

Amazon Kindle edition

Soft-bound edition

In Germany:

Amazon Kindle edition

Soft-bound edition

In France:

Amazon Kindle edition

Soft-bound edition

The Kindle edition's ASIN is B00IXRCC4Y. For the print edition the ISBNs are 1481955853 (ISBN-10) or 978-1481955850 (ISBN-13). For the most part bookstores will not find it attractive to stock the books but they may special-order them at customer request. 

Nevinson, Column on the March

C.R.W. Nevinson, “Column on the March.” One of dozens of illustrations in The Plan That Broke the World.

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