A dominant principle that guided combatants through much of history was "to the victor belong the spoils".
Emer de Vattel, in The Law of Nations (1758), presented an early codification of the distinction between annexation of territory and military occupation, the latter being regarded as temporary, due to the natural right of states to their "continued existence". The
Hague Convention of 1907 codified these customary laws, specifically within "Laws and Customs of War on Land" (Hague IV); 18 October 1907: "Section III Military Authority over the territory of the hostile State". The first two articles of that section state: Art. 42. Territory is considered occupied when it is actually placed under the authority of the hostile army. The occupation extends only to the territory where such authority has been established and can be exercised. Art. 43. The authority of the legitimate power having in fact passed into the hands of the occupant, the latter shall take all the measures in his power to restore, and ensure, as far as possible, public order and safety, while respecting, unless absolutely prevented, the laws in force in the country. In 1949 these laws governing the occupation of an enemy state's territory were further extended by the adoption of the
Fourth Geneva Convention (GCIV). Much of GCIV is relevant to
protected civilians in occupied territories and
Section III: Occupied territories is a specific section covering the issue. Under GCIV, protected civilians in general are: • those "who ... find themselves ... in the hands of a Party to the conflict or Occupying Power of which they are not nationals". This generally refers to civilians of an enemy state, including refugees, and stateless persons. •
neutral citizens in occupied territory regardless of diplomatic status. •
refugees of the occupying power prior to hostilities who cannot be arrested, prosecuted, or deported from occupied territory except for crimes committed after the conflict or beforehand which are also crimes under the law of the occupied state that would permit peacetime
extradition as defined under
Article 70. Nationals of an enemy state not a signatory or acceded to GCIV are not protected by it. Neutral citizens who are in the home territory of a belligerent nation if their country of origin has diplomatic ties or elsewhere outside occupied territory are not protected. Nationals of a
co-belligerent (allied) state which holds diplomatic ties with a belligerent nation are excluded from protection in both locations.
Article 6 of GCIV restricts the length of time that most of the convention applies: The present Convention shall apply from the outset of any conflict or occupation mentioned in Article 2. In the territory of Parties to the conflict, the application of the present Convention shall cease on the general close of military operations. In the case of occupied territory, the application of the present Convention shall cease one year after the general close of military operations; however, the Occupying Power shall be bound, for the duration of the occupation, to the extent that such Power exercises the functions of government in such territory, by the provisions of the following Articles of the present Convention: 1 to 12, 27, 29 to 34, 47, 49, 51, 52, 53, 59, 61 to 77, 143. GCIV emphasised an important change in international law. The
United Nations Charter (26 June 1945) had prohibited war of aggression (See articles 1.1, 2.3, 2.4) and GCIV
Article 47, the first paragraph in Section III: Occupied territories, restricted the territorial gains which could be made through war by stating: Protected persons who are in occupied territory shall not be deprived, in any case or in any manner whatsoever, of the benefits of the present Convention by any change introduced, as the result of the occupation of a territory, into the institutions or government of the said territory, nor by any agreement concluded between the authorities of the occupied territories and the Occupying Power, nor by any annexation by the latter of the whole or part of the occupied territory.
Article 49 prohibits the forced mass movement of protected civilians out of or into occupied state's territory: Individual or mass forcible transfers, as well as deportations of protected persons from occupied territory to the territory of the Occupying Power or to that of any other country, occupied or not, are prohibited, regardless of their motive. ... The Occupying Power shall not deport or transfer parts of its own civilian population into the territory it occupies.
Protocol I (1977): "Protocol Additional to the
Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts" has additional articles which cover occupation but many countries including the
U.S. are not signatory to this additional protocol. In the situation of a territorial cession as the result of war, the specification of a "receiving country" in the peace treaty merely means that the country in question is authorized by the international community to establish civil government in the territory. The military government of the principal occupying power will continue past the point in time when the peace treaty comes into force, until it is legally supplanted. "Military government continues until legally supplanted" is the rule, as stated in
Military Government and Martial Law, by William E. Birkhimer, 3rd edition 1914. == Qualification of a territory as occupied ==