who is responsible for protecting citizens from internal threats
Internal security Governmental responsibility for internal security will generally rest with an interior ministry, as opposed to a defence ministry. Depending on the state, a state's internal security will be maintained by either the ordinary police or law enforcement agencies or more militarised police forces (known as Gendarmerie or, literally, the Internal Troops.). Other specialised internal security agencies may exist to augment these main forces, such as border guards, special police units, or aspects of the state's intelligence agencies. In some states, internal security may be the primary responsibility of a secret police force.