Human intelligence (HUMINT) represents the oldest and most elemental form of intelligence activity. Although technological advances in technical intelligence services such as signals and imagery have lowered the profile of HUMINT activities, in recent years the focus on terrorism and nonstate actors has again emphasized the importance of HUMINT. Specifically, military branches have made HUMINT a priority, as many criminal and/or terrorist groups have reduced their visibility and use of communications technologies open to signal intercepts.

Fundamentally, HUMINT consists of gathering information through infiltration, interviews—collecting data from people and institutions—and extracting any information of tactical and/or strategic value. This entry discusses the types of HUMINT activities, the training and skills required for HUMINT operators, the steps in handling information, and recent operations.