In World War I, many of the intelligence disciplines still in use today were deployed for the first time: aerial photography, signals intercept, interrogation teams, and counterintelligence agents.
[2] Van Deman founded the Corps of Intelligence Police to conduct undercover investigations of individuals and organizations.
Van Deman was equally concerned about the loyalty of recent immigrants being drafted into service.
To protect the force, two soldiers within each company were appointed to secretly report on any suspicious activity, using the guidelines contained in a confidential pamphlet, “Provisional Counter-Espionage Instructions”.
After the attack on Pearl Harbor, the CIP was reorganized, expanded, and renamed the Counter Intelligence Corps.