How Scholars and Librarians Became the Unlikely Spies of World War II by Elyse Graham
I have spent much of my life as an academic and had little in the way of experience as a spy or secret agent. This book tells the story of how the U.S. did not have any intelligence agencies early in the 20th Century. When the need arose it had to start from scratch with minimal assistance from future allies like the British. At first they had an ad hoc collection of U.S. citizens that happened to be present in the areas of conflict in the Mid-East leading up to World War I, including U.S. oil company employees looking for oil and archeologists digging ancient ruins. Soon the U.S. opened training schools to train academics who used their research skills to collect valuable information and much of that information was found in libraries all over the world.
The book concentrates on two time periods: just prior to the U.S. entry into WWI and just prior and during the U.S. entry in WWII. It is well-written and fun to read. And best of all you get some good advice about how to be a spy, including how to create a convincing cover story and the best way to kill someone if you are ordered to make a hit!