William B. Breuer landed with the first assault waves in Normandy on D-Day (June 6, 1944), then fought across Europe. Later, he founded a daily newspaper on a string in Rolla, Missouri, and after that, a highly successful public relations firm in St. Louis, Missouri. He had been writing books full time since 1982
I picked up this book at a used book store and was intrigued by it. It is amazing to me how few books are available on the subject of Nazi espionage in the Allied countries. Perhaps the US Government was so effective at finding and neutralizing the Nazis in the US that German espionage was not a factor in the war. This book helped to answer some of the questions.
The main thrust of this book was the famous Duquesne spy ring, headed by the notorious South African spy who operated for Germany in both World Wars. The book also went into the Nazi sympathizers who belonged to the German-American Bund, a pro-Nazi organization that held rallies in New York City among other places in the 1930s. The German operation whereby American sympathizers with the Nazi regime were landed in New York toward the beginning of the war, but all of the spies were rounded up relatively quickly. The rest of the book focused on the brilliant US counterintelligence operations which effectively removed some of the German operatives while turning others to provide disinformation to the Germans.
This is interesting history of an area that is surprisingly under-reported, at least in the English language. It is highly recommended for those who enjoy WWII history.