A sneak attack - hundreds of Japanese bombers blow up the American naval base at Pearl Harbor, leaving over 2,000 military dead. America recoils in shock and grief, as well as fear for their national security that spies and saboteurs lived among them. The attack created an overwhelming unity of purpose - to expose the enemy at home and to defeat the enemy abroad. This book is part of that war effort.
Link to the book: How To Spot a Jap (1942-US Army)
Clearly, but it's a poor effort when the instructional manual that attempts to teach facts is out of touch with reality. Not very useful or helpful when it comes to identifying friend or foe when the so-called facts provided to soldiers are utter bilge. The Nazis had similar propaganda explaining how to identify Jews by "racial" characteristics.