The DIA (Defense Intelligence Agency of the United States) was established by Secretary of Defense Robert McNamara in order to gather and control military intelligence. It is important to note that the CIA is an intelligence agency that is under the direct supervision of the US President, while the DIA lies under the jurisdiction of the Department of Defense. Moreover, the CIA primarily handles political intel, while the DIA deals mainly in military intel.

Current freelance military analyst Natasha Romanenko once worked for the DIA. Her expertise led her to be recruited to Solid Snake's mission support team during the Shadow Moses Incident.