Secret Armies: Exposing Hitler's Undeclared War on the Americas

John L. Spivak’s Secret Armies: The New Technique of Nazi Warfare, originally published in February 1939, examines the clandestine operations of Nazi agents in the U.S., Mexico, and Central America during the late 1930s. Spivak chronicles their efforts in domestic propaganda, military espionage, and attempts to undermine U.S. relations with neighboring countries. Despite the dated methods of communication, the book highlights the enduring motives and principles behind such activities, revealing how these strategies surprisingly intensified American support for the Allies rather than deterring intervention. This work offers crucial insights into the history of espionage that remain relevant for modern society.