Treacherous Passage


Treacherous Passage

Germany's Secret Plot against the United States in Mexico during World War I

Bill Mills

256 pages
25 illustrations, 1 table, index


January 2017


$29.95 Add to Cart
eBook (PDF)

(Requires Adobe Digital Editions)

January 2017


$29.95 Add to Cart
eBook (EPUB)

(Requires Adobe Digital Editions)

January 2017


$29.95 Add to Cart

About the Book

While the Great War raged across the trench-lined battlefields of Europe, a hidden conflict took place in the distant hinterlands of the turbulent Mexican Republic. German officials and secret-service operatives plotted to bring war to the United States through an array of schemes and strategies, from training a German-Mexican army for a cross-border invasion, to dispatching saboteurs to disrupt American industry, and planning for submarine bases on the western coast of Mexico.

Bill Mills tells the true story of the most audacious of these operations: the German plot to launch clandestine sea raiders from the Mexican port of Mazatlán to disrupt Allied merchant shipping in the Pacific. The scheme led to a desperate struggle between German and American secret agents in Mexico. German consul Fritz Unger, the director of a powerful trading house, plotted to obtain a salvaged Mexican gunboat to supply U-boats operating off Mexico and to seize a hapless tramp schooner to help hunt Allied merchantmen.

Unger’s efforts were opposed by a colorful array of individuals, including a trusted member of the German secret service in Mexico who was also the top American spy, the U.S. State Department’s senior officer in Mazatlán, the hard-charging commander of a navy gunboat, and a draft-dodging American informant in the enemy camp. Full of drama and intrigue, Treacherous Passage is the first complete account of the daring German attempts to raid Allied shipping from Mexico in 1918.

Author Bio

Bill Mills is an espionage writer and historian. He is the author of The League: The True Story of Average Americans on the Hunt for World War I Spies.


"A lively read . . . not only a good cloak and dagger tale, but [Treacherous Passage] also throws further light on the still-not fully documented German efforts to carry on covert operations against the United States during the Great War."—A. A. Nofi, Strategy Page

"An excellent book casting light on one segment of the troubled relationship the United States has often had with Mexico."—Charles H. Bogart, Journal of America's Military Past

"Mills presents the readers with a lively and compelling story about lesser known events on Mexico's southwestern Pacific coast. In so doing Mills alerts his audience to the significance of these events in the larger context of German and US intelligence operations in Mexico."—Thomas M. Leonard, Latin American Research Review

“Barbara Tuchman meets John Le Carré in Treacherous Passage, a gripping story of espionage and intrigue that reminds us that World War I truly was a global war fought on many fronts.”—Christopher Capozzola, author of Uncle Sam Wants You: World War I and the Making of the Modern American Citizen


“The Zimmermann Telegram is infamous. But the story of Germany’s World War I plot to launch sea raiders against U.S. commercial shipping from Mazatlán remains an episode almost as obscure today as it was in 1918. This book is a revelation.”—Alan Axelrod, author of Miracle at Belleau Wood and The Battle of Verdun 

Table of Contents

List of Illustrations


Prologue: "The Morelos Will Be Ours"

1. A Simple Business Transaction

2. "I Will Shoot You Down like a Dog!"

3. The Alexander Agassiz

4. For Honor and Fatherland

5. "She Is an Outlaw and a Dangerous Enemy"

6. "If You Want to Get the Best of Uncle Sam, Get Up before You Go to Bed"

7. "The Germans Are After You"

8. United States of America vs. Alexander Agassiz

9. Going For Broke




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