<P> Internal security, or IS, is the act of keeping peace within the borders of a sovereign state or other self - governing territories . generally by upholding the national law and defending against internal security threats . Responsibility for internal security may range from police to paramilitary forces, and in exceptional circumstances, the military itself . </P> <P> Threats to the general peace may range from low - level civil disorder, large scale violence, or even an armed insurgency . Threats to internal security may be directed at either the state's citizens, or the organs and infrastructure of the state itself, and may range from petty crime, serious organised crime, political or industrial unrest, or even domestic terrorism . Foreign powers may also act as a threat to internal security, by either committing or sponsoring terrorism or rebellion, without actually declaring war . </P> <P> 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 . </P> <P> The level of authorised force used by agencies and forces responsible for maintaining internal security might range from unarmed police to fully armed paramilitary organisations, or employ some level of less - lethal weaponry in between . For violent situations, internal security forces may contain some element of military type equipment such as non-military armored vehicles . </P>

Who is responsible for protecting citizens from internal threats