Internment is the imprisonment of people, commonly in large groups, without charges or intent to file charges. The term is especially used for the confinement "of enemy citizens in wartime or of terrorism suspects". Thus, while it can simply mean imprisonment, it tends to refer to preventive confinement rather than confinement after having been convicted of some crime. Use of these terms is subject to debate and political sensitivities. The word internment is also occasionally used to describe a neutral country's practice of detaining belligerent armed forces and equipment on its territory during times of war, under the Hague Convention of 1907.

A neutral country is a state that is neutral towards belligerents in a specific war or holds itself as permanently neutral in all future conflicts. As a type of non-combatant status, nationals of neutral countries enjoy protection under the law of war from belligerent actions to a greater extent than other non-combatants such as enemy civilians and prisoners of war. Different countries interpret their neutrality differently: some, such as Costa Rica have demilitarized, while Switzerland holds to "armed neutrality", to deter aggression with a sizeable military, while barring itself from foreign deployment.