In the early days of the Vietnam War, the U.S. lost an alarming number of pilots and aircraft. To reverse that trend, a team was assigned to analyze U.S. military operations. The team, "Purple Dragon," discovered that crucial planning information was being disclosed through routine patterns of behavior. Countermeasures were quickly initiated.

Purple Dragon’s analytic process, called OPerations SECurity or OPSEC, was used by the military for the next 20 years. In 1988, President Reagan formalized its use throughout the government and created the IOSS to provide training and guidance to the national security community.