The NSO was created as a fall-out of the Dimka coup. Prior to the coup, internal security and intelligence was handled by the police Special Branch, a Secret Police, while external intelligence was conducted by the Research Department (RD), a unit of the External Affairs ministry. The Special Branch had failed to obtain intelligence about the coup and the coup plotters before the coup was executed; the Inspector General of police at the time MD Yussuf excused this failure as the inability of the Special Branch to police the military. The police simply lacked the legal backing to conduct intelligence operations on the military.