This piece is part of a recurring series that aims to be a complete guide to the laws of war. You can read previous entries here.
International Humanitarian Law (IHL) provides extremely detailed protection in situations of military occupation. The nations of the world—who collectively make the laws of IHL—all have an interest in preserving their sovereign territory from annexation or conquer, which is prohibited under international law. In wartime situations where an invading armed force seizes control over a territory, nations’ Westphalian priorities are served by laws which require occupying powers to generally respect, as far as possible, the existing laws and institutions of the occupied territory, and by laying down strong and detailed protection for the civilian population.
In many respects, military occupation is a strange state of affairs. It lies somewhere between war and peace—military hostilities connected to the invasion have ceased, but the enemy has assumed temporary control. Its rules belong to a body of law with one Latin name (ius in bello, the laws in war) which is entirely neutral as to the outcome of a conflict, but are informed by the goals of completely separate and independent body of law with a different Latin name (ius ad bellum, the laws against war), which seeks to preserve the status quo by prohibiting annexation of territory.
The Fourth Geneva Convention of 1949 (or GC IV), the First Additional Protocol of 1977 (or AP I), and the Hague Regulations of 1907 seek to address these issues and lay down measures to protect those who find themselves in occupied territory.
What does it mean for a territory to be occupied? Simply, that a foreign hostile army has assumed actual authority over a territory to the exclusion of the legitimate power and without its consent. Most often, occupation results from a ground invasion where the territorial army is defeated or forced to surrender, with the invading army assuming control over the occupied territory. Extraneous factors are, for our current purposes, irrelevant: the law of occupation applies if those criteria are satisfied, regardless of whether the occupying force is waging a legal or illegal war, whether their actions are morally justified or not, or whether they fully respect IHL or routinely commit war crimes.
Whereas in ancient times land was routinely won and lost by the sword, today acquisition of territory by military conquest is prohibited, and no territorial acquisition or special advantage resulting from an act of aggression is or may be recognized as lawful. This is an area of international law which the nations of the world are keen to enforce—each recognizes that permitting territorial conquest would open their nation up to attack (and would open the floodgates to destabilizing wars elsewhere). In any event, many modern wars are not fought with that aim—the 2003 coalition invasion of Iraq had many goals, but annexation of Baghdad was probably not one of them.
The law of occupation applies for so long as the occupying power retains its unconsented-to authority over the territory. A hostile army must initially be physically present in the territory for the law of occupation to be triggered, but thereafter may continue to exercise effective control even after a withdrawal of troops (a question of fact in each case).
Be sure to note that we’re not discussing here the conduct of hostilities, the legal framework which applies when opposing forces are attacking each other with kinetic force and governs issues such as what does and does not constitute a military objective which may be directly attacked. (We will discuss the conduct of hostilities in the next article in this series.) During a military campaign (including an invasion), the laws on the conduct of hostilities provide that death, injury, and destruction of objects may be lawful. Once an invading force has seized authority over a territory from the legitimate power and become an occupying force, the protective law of occupation discussed in this article starts to apply.
All situations of occupation trigger the application of each of the four Geneva Conventions of 1949 and the laws of international armed conflict (IAC). This is so even if the occupation meets with no armed resistance and so there isn’t an “conflict” between the occupier and the territorial state in the traditional sense, such as with the unopposed German occupations of Denmark and parts of Czechoslovakia during World War II.
A hostile army does not need to control all of the territory of the nation it has invaded for the laws of occupation to apply; occupation extends only to the territory where such authority has been established and can be exercised. It’s theoretically possible for an invading force to occupy only a single village.
There is no analogous notion of occupation in non-international armed conflicts (NIACs), being conflicts between a state and a non-state armed group or between multiple non-state armed groups. (This is one of the two major areas in which the law of IAC and NIAC differ, along with the prisoner of war regime.) The nations of the world would never agree to laws which may give rebel or insurgent groups a sheen of legitimacy by vesting the public duties of an occupying power in them. We therefore speak of non-state armed groups “controlling” territory, but never “occupying” it. (Indeed, one of the required conditions for the application of Additional Protocol II in NIAC is that a non-state armed group exercises control over part of a territory). This is an important gap in the law, as most conflicts currently being fought worldwide are NIACs. The general protections laid down in Article 3 common to the four 1949 Geneva Conventions apply to protect persons not taking part in the conflict, and human rights law similarly continues to provide important protections in such scenarios.
According to the Geneva Academy’s Rule of Law in Armed Conflict project, current situations of military occupation worldwide include Morocco’s occupation of the Western Sahara, Turkey’s occupation of northern Cyprus, and Russia’s occupation of parts of Georgia, Ukraine, and Moldova. The most well-known situation of occupation passed fifty years’ duration in 2017—Israel has continuously occupied the West Bank (including East Jerusalem) and the Gaza Strip in Palestine since the Six-Day War of 1967.
Additional Protocol I grants fundamental guarantees of protection and humane treatment to all persons in occupied territory. These include general guarantees of respect for their person, fair trial and due process guarantees, and prohibitions against murder, torture, corporal punishment, enforced prostitution, and collective punishments.
In addition, the Fourth Geneva Convention grants special protection to protected persons who are in territory occupied by a power of which they are not nationals. In occupied territory, any person who is not a national of the occupying power is classified as a protected person, unless they are a protected person under any of the first three Geneva Conventions, or are a national of a co-belligerent ally of the occupying power and have access to diplomatic representation. Persons who were considered as refugees before the beginning of hostilities are also protected persons.
Protected persons cannot be deprived of the benefits that the Fourth Convention gives to them by any purported annexation of the occupied territory, by any agreements entered into between the occupier and the legitimate sovereign, or by any changes introduced to the occupied territory’s institutions or government. This is an extremely important provision, but be sure to understand what it does and doesn’t claim to do—the rule doesn’t itself prevent these actions from happening or make them unlawful, but simply provides that they cannot be used as vehicles to curb benefits owed to civilians. (For example, the occupying and occupied powers may well lawfully enter into agreements on various topics, while a nation may claim to have annexed territory but that claim will be ineffective and unlawful under other provisions of international law outside of GC IV.) In addition, protected persons may not under any circumstances renounce the rights owing to them under the Convention.
Protected persons who are not nationals of the occupied territory have the right to leave, subject to the same restrictions as those placed on protected persons in non-occupied enemy territory. The right to leave may be blocked by the occupying power only if it is contrary to the national interests of the state (which may be the case where an individual protected person may be expected to return to their home nation and join the military effort against the occupying power), or where a group of protected persons are collectively critical to public administration in the occupied territory (for example because a large number are sitting judges and their departure would adversely affect the judicial system).
Not surprisingly, the civilian population of an occupied territory does not owe allegiance to the occupying power. An occupying power cannot compel protected persons to serve in its forces—doing so is a grave breach of GC IV such that every country in the world is bound to search for and prosecute or hand over for trial any person on their territory suspected of doing so. No pressure or propaganda aimed at voluntary enlistment is permitted, and it is forbidden to compel the inhabitants of occupied territory to swear allegiance to the hostile power. Similarly, an occupying power cannot compel a protected person to undertake any work which involves the obligation of taking part in military operations.
An occupying power is prohibited from deporting protected persons from occupied territory, and from transferring its own population into occupied territory. These important prohibitions exist for a number of reasons—the ban on mass and individual deportations in response to the horrors of World War II and to keep families together and preserve life as normal, and both restrictions to preserve the economic situation of the occupied territory and to prevent what we might call annexations by stealth. The International Court of Justice has held that the separation wall built along the so-called “Green Line” of the West Bank, and Israeli settlements in Occupied Palestinian Territory, violate the latter prohibition as they are each designed to contribute to alterations to the demographic composition of the Occupied Palestinian Territory. Deportations of protected persons from occupied territory are grave breaches of GC IV, and both deporting protected persons and transferring an own population from/to occupied territory are war crimes in the International Criminal Court.
An occupying power may not arbitrarily deprive civilians who have not committed any offense of their liberty. An occupying power may only subject protected persons in occupied territory to internment in two cases: where they have committed an offense intended to harm the occupying power, or if necessary for imperative reasons of security. Interned civilians have the right to appeal their internment, and to have it reviewed every six months. The standards of internment required for protected persons in occupied territory are the same as for those in non-occupied territory, which broadly follow the standards of internment for prisoners of war: including as to internees’ maintenance and medical attention, the standard of their accommodation, provision of food and clothing, freedom of religion, election of internee representatives, entitlement to send and receive correspondence, and the imposition of penal and disciplinary sanctions.
The destruction of real or personal property by occupying forces is prohibited except where rendered absolutely necessary by military operations. Pillage—the forcible taking of private property—is prohibited by IHL, is a war crime in IAC and NIAC, and is prohibited in domestic military manuals all over the world. Private property cannot be confiscated, except that war material may be seized so long as it is restored and compensation fixed when peace is made.
The International Committee of the Red Cross has the right to visit occupied territories and to conduct private interviews with protected persons. The ICRC carries out these visits in accordance with the same principles as with its visits to prisoners of war.
Military occupation throws life in the occupied territory into limbo—the legitimate authorities have been defanged, and while the occupying force exercises de facto authority, it has not assumed (and may not assume) the status of lawful sovereign. Until the occupation ends, life must go on and governance of the occupied territory is still needed.
The law of occupation seeks to balance competing interests: of the occupying power in ensuring the safety of its forces; of the territorial sovereign in maintaining its legal authority over the territory; and the civilian population in being protected from attack and maltreatment and ensuring that life continues as normal so far as possible.
The fact that an occupation has been established does not invalidate existing laws in place, and the occupying power may not institute new laws as it pleases or extend its own legislation over the occupied territory. The law of occupation therefore grants an occupying power a limited authority to create new laws over the occupied territory. Crucially, an occupying power may only introduce changes for the duration of the occupation.
The general rule is that the occupying power must take all the measures in its power to restore and ensure public order and civil life while respecting, unless absolutely prevented, the laws in force in the country. The Fourth Geneva Convention further delimits the boundaries of the occupying power’s lawmaking authority by providing that penal laws are generally to remain in force and may only be repealed or suspended if they constitute a threat to the occupying power’s security. Courts and tribunals of the occupied territory continue to function, subject only to considerations of security and ensuring the effective administration of justice. An occupying power may only make new laws essential to enable it to fulfil its obligations under GC IV, to maintain the orderly government of the territory, and to ensure its security.
(Fun fact: the general rule above comes from the 1907 Hague Regulations, whose French text is the only authentic version as French was the main diplomatic working language at that time. The most widely-used English translation refers to “public order and safety”, an imprecise translation of the original French phrase “l’ordre et la vie publics”, which should be more accurately represented in English as “public order and civil life”, a much broader term. Mistranslations pop up in various fields of international law, but thankfully this is one of the few notable instances in IHL. While we’re here: the 1949 Geneva Conventions were drafted in equally authentic English and French versions, while by 1977 it was seen fit to create equally authentic versions of the two Additional Protocols in the six official languages of the United Nations—Arabic, “Chinese” (i.e., Mandarin), English, French, Russian, and Spanish. The Conventions have been officially translated into at least 55 languages, but all parties remain bound by the authentic versions and cannot claim that translated versions prevail in the case of any differences.)
An occupying power has obligations toward the civilian population under what human rights law calls economic, social, and cultural rights—including the right to free education, the right to food, the right to health, and the right to work. An occupying power must facilitate the proper working of existing children’s education and care institutions, and make arrangements for maintenance and education of orphaned or separated children if local institutions are inadequate. It has the duty of ensuring food and medical supplies of the civilian population, and it must import provisions if the resources of the occupied territory are inadequate. The occupying power must ensure and maintain public health and existing medical and hospital establishments and services, and must ensure the provision of basic needs such as clothing, bedding, means of shelter, and objects necessary for religious worship. There is an absolute obligation to allow the free passage of humanitarian assistance and relief consignments and to guarantee its protection. Measures aimed at creating unemployment in occupied territory or at restricting the opportunities offered to workers in order to induce them to work for the occupying power are prohibited.
Conceptually, an occupying power has two types of obligations under the law of occupation: positive obligations (to do something, such as to provide for the schooling of young children in the occupied territory), and negative obligations (to not do something, such as to not attack the civilian population). Negative obligations kick in and must be respected immediately—they only require refraining from certain conduct and so there is no argument that they cannot be applied right away. On the other hand, positive obligations are often obligations of means and may take effect over time. For example, while an occupying power would be expected to provide food and water for the civilian population right from the beginning of an occupation, it may not be in a position to immediately institute a workable health system where one did not exist before, and has some measure of leeway in marshalling its resources toward that obligation. Some affirmative steps may be able to be taken in short order: the Coalition Provisional Authority justified redrafting Iraq’s labor code on the grounds that, as a State party to International Labour Organization Conventions, Iraq was obliged to “take affirmative steps towards eliminating child labor.”
Except concerning the protection of the occupying power’s security, local laws remain in force and local courts remain competent. The occupying power may not alter the status of public officials or judges in occupied territory
When an occupying power enacts new penal laws, civilians must benefit from regular trials in the occupying power’s military courts. This is one of the rare areas where IHL departs from human rights law, where trial by a civilian court would ordinarily be required. Courts must take into account that the accused is not a national of the occupying power. Accused persons must benefit from fair and regular trial guarantees, including being informed in writing of the charges against them, rights to an adequate defense and to call witnesses, access to an interpreter, and the right to an appeal. Protected persons must be detained and serve their sentence in the occupied country. While detained, they must enjoy conditions of food and hygiene to keep them in good health, and receive medical attention as needed. Women are to be held in separate quarters and under the direct supervision of women.
Public property may be administered by the occupying power, but only under the rules of usufruct, which as the name suggests broadly means that the occupying power may use and exploit the fruits of public property such as buildings and water reservoirs.
The laws of military occupation serve to protect the civilian population in their time of greatest vulnerability and to protect territory from conquer. Upholding and respecting the principles discussed above are crucial for striving for a more peaceful world.
The next installment of this series will cover the conduct of hostilities.