Introduction

1Since ancient times armies have occupied and acquired additional territory by means of warfare. Until the 19th century, military occupation of an adversary’s territory resulted in the transfer of property and sovereignty to the occupying power. The new sovereign could quite freely dispose of the territory and treat its inhabitants as it wished. The nature of belligerent occupation, as we know it today, developed largely in the period between the Lieber Code of 1863 and the Hague Regulations of 1907. While the definition of occupation continued to be subject to some controversy, it became apparent that belligerent occupation is only of a temporary nature, that the powers of the occupant are limited and that invasion alone should not decide over the future status of a territory. Essential for the definition of belligerent occupation as crystallised in Article 42 of the 1907 Hague Regulations is the idea that occupation must be both actual and effective. For belligerent occupation to be established, the armed forces that have invaded the enemy’s territory must have gained de facto control over a given area through their physical presence and must have substituted their authority for that of the legitimate sovereign. As a consequence, a state of belligerent occupation seems to be clearly distinguishable from the invasion phase during which such de facto control and authority may not yet have been acquired.

2The atrocities of World War II, however, made evident the insufficiencies of the 1907 Hague Regulations and its rules on belligerent occupation. The Fourth Geneva Convention subsequently elaborated on, inter alia, the rules applicable to occupied territories. As the 1949 Geneva Conventions lack a definition of occupation, the question arises whether these provisions apply only once a state of occupation as set out in Article 42 of the 1907 Hague Regulations has been established, or whether Section III of the Fourth Geneva Convention relative to occupied territories follows its own rules on applicability.

3The ICRC Commentary on the Fourth Geneva Convention advocates the so-called “functional beginning” approach to belligerent occupation.1 Accordingly, the rules on occupied territories of the Fourth Geneva Convention apply as soon as a “protected person” falls into the hands of a party to the conflict present in enemy territory. Consequently, the application of these rules would not depend upon the existence of a state of occupation as defined in the 1907 Hague Regulations and there would not be an intermediate period between invasion and a state of occupation. This holds true for at least the Fourth Geneva Convention and as far as individuals are concerned. The theory is called “functional beginning” because the provisions on occupation would become applicable in a progressive manner and on the basis of the contact occurring between the local population and the invading troops. According to the famous example given in the ICRC Commentary, even a patrol that penetrates into enemy territory must respect the Fourth Geneva Convention in its dealings with civilians and must not, for instance, deport them, for that would be contrary to Article 49 of the Fourth Geneva Convention.2

4It is argued in this paper that the application of the functional beginning of occupation theory is the preferred solution. This would fill probable gaps of protection during the invasion phase and would be in line with the object and purpose of the Geneva Conventions. Moreover, an analysis of the rules relating to belligerent occupation suggests that invading troops would not be disproportionally burdened with additional and impractical obligations. On the contrary, the wording of most of the relevant articles leaves enough leeway to adapt and take into account the difficult circumstances prevailing during an invasion. Furthermore, the functional beginning of belligerent occupation approach would also give invading powers certain rights, such as a legal basis for security measures and internment.