- The CIA is responsible for gathering intelligence and carrying out covert operations outside the US.
- The FBI is responsible for internal counterintelligence and federal criminal investigations.
- The NSA is responsible for gathering intelligence specifically from communications networks.
- Homeland Security is responsible for counter-disaster and disaster response operations, mainly terrorism and natural disasters.
- DOD is the department of defense, the government body that oversees the armed forces and several intelligence agencies (including the NSA and DIA).
- The DIA is the Defense Intelligence Agency, which is responsible for intelligence specifically regarding military affairs.
- The DEA is the Drug Enforcement Administration. They are somewhat like a drug-specific FBI.