In his study of the law of occupation, the author has decided to focus on questions relating to the use of armed force in the occupied territory. The choice of this focus is justified in the first chapter of the book and mainly based on two reasons.

The first reason for this focus on the use of force is justified by the author in reference to the fact that the ICRC has identified the legal framework governing the use of force by an occupying power to be one the challenges raised by recent examples of occupation and that therefore “there is a need to clarify how the rules governing law enforcement and those regulating the conduct of hostilities interact in practice in the context of an occupation” (p.1). This question relates to the very nature of occupation given that it is precisely situated somewhere between war and peace and based on the fact that the occupying power is in charge of maintaining law and order in the occupying power (law enforcement) whilst at the same time having to operate in the reality of war (potential resumption of conduct of hostilities). The interaction between law enforcement and conduct of hostilities (chapter 5) has in the present reviewer’s opinion been rightly identified as one of the legal issues which still merits further attention in relation to the law of occupation and hence is definitely an issue that is worth exploring further in the context of this book.

The author decided to not only focus on this particular issue but looks more broadly at the issue of the use of armed force in the occupied territory. The book offers a broader perspective on the use of force in occupied territories in two ways. First, whilst the above-mentioned need for clarification mainly relates to the regime regulating occupation under international humanitarian law (IHL) and to some extent also its interaction with human rights law (HRL), the author decided to also assess the issue of the use of force in occupied territories under the jus ad bellum regime (chapter 3). Second, the author decided to not only focus on the use of force by the occupying power but also assesses the legitimacy of the use of force against the occupying power, both from a jus ad bellum perspective (chapter 3) and from an IHL perspective (chapter 4).

The second reason given to justify the specific focus on the use of force is the fact that “a comprehensive study on the use of armed force in occupied territory has not been published yet” (p. 4). Indeed in most books dealing with the law of occupation, the question of the use of force is only incidentally addressed as part of many other relevant issues concerning the law of occupation and this mainly from an IHL/IHRL perspective. There is thus “no comprehensive work, studying this topic from just ad bellum, international humanitarian law, and international human rights law perspectives” (p. 9).

In light of the above, this book is definitely a welcome addition to the existing literature on the law of occupation. It furthermore presents interesting points, which are well argued and presented in a very structured manner. The book also includes adequate reference to actual cases and case-law were needed. The present reviewer definitely found it to be a captivating read.

After having assessed the idea behind this book and its added value in relation to the existing literature on the law of occupation, the different substantive chapters will now be briefly assessed, focussing on some of the main interesting points/potential points of contention. This assessment will start with chapter two given that chapter one mainly established the scope of the book and has already been addressed in the first part of this book review.

Chapter two presents an overall introduction to the law of occupation with a focus on those points having a further relevance for the study at hand. It presents a quite classical overview of the system. It starts off with an overview of the origins and further development of the law of occupation. It then addresses the factual character of occupation. In this regard, it is further emphasized that given that the existence of a situation of occupation is a factual assessment “it is irrelevant whether the occupation was established in violation of international law”. This has important relevance also in relation to the jus ad bellum. Indeed even if the occupation was established in violation of jus ad bellum rules this would have no consequences for the applicability of the law of occupation. This is in line with the general separation between the jus ad bellum and jus in bello (IHL) regimes. The part relating to the factual character of occupation also addresses the questions relating to the beginning and end of occupation. The author correctly states that “the debate regarding whether a territory is occupied or not focuses mainly on the degree of authority exercised by the hostile state in order to occupy the territory” (p. 35) or in other words the effective control test. The difficulties associated with the actual application of the effective control test will not be dealt with in the framework of this review given that this is not actually that relevant for the main focus of the book which is the use of armed force in the occupied territory. In relation more specifically to the law, the author emphasises that the law of occupation is a component of IHL but also that it is an open system and that “the application of the law of occupation does not bar the application of the other branches of law” (p. 44). This is relevant for the study at hand given that the author is not only going to assess the question of the use of force in the occupied territory under IHL but also under the jus ad bellum and HRL systems. Finally, the author also recalls some of the main characteristics of occupation: 1) occupation does not transfer sovereignty; 2) occupation is a provisional state of affairs and 3) the occupying power is temporarily in charge of administrating the occupied territory and is more particularly responsible for maintaining law and order in said territory. These are all elements that will be important for the subsequent assessments provided in the book.

Chapter 3 deals with the question of the applicability of jus ad bellum and self-defence to the use of armed force in the occupied territory. From the outset it is clear that the author is going to conclude that the jus ad bellum rules are largely inapplicable to the use of armed force in the occupied territory. In reference to what was mentioned in the introduction of the book (i.e. the use of armed force is often the precursor for the occupation – p. 2), and in light of the strict separation between the jus ad bellum and the jus in bello to present reviewer also definitely believes jus ad bellum to not be relevant for the use of force once the occupation has been established. In other words, as with all assessments relating to jus ad bellum these relate to the assessment of the validity of the use of force of which the armed conflict is a consequence but do not further concern the rules regulating the armed conflict once it has come into existence. The present reviewer does however understand why the author nevertheless decided to address this issue in the context also of an existing occupation, at least when it comes to the use of force by the occupying power. Indeed, as is also highlighted in the book, Israel has for example often used the right to self-defence (which is a part of the jus ad bellum regime) as a way to justify some of its actions in relation to the Occupied Palestinian Territories and hence it is at the very least interesting to assess whether such a use of the right of self-defence would be accepted (which the author correctly proves not to be the case). One point that the present reviewer found particularly interesting in the reasoning relating to the right to self-defence of the occupying power, was the assessment of the ‘unable or unwilling doctrine’ in order to justify acting in self-defence against non-state actors presenting a threat within the occupied territory. If one were to accept the validity of this doctrine in the first place (which is very contested under international law) it would indeed present an important challenge in relation to situations of occupation given that by definition occupation renders the legitimate/ousted government (temporarily) unable to deal with security threats within the occupied territory given that the effective control over the territory is in the hands of the occupying power and consequently the latter is in charge of maintaining law and order in the occupied territory.

Whereas the assessment of the potential jus ad bellum implications in relation to the use of force by the occupying power presents some though-provoking elements as was just mentioned, the assessment of said implication for the use of force against the occupying power presents some challenges in the present reviewer’s opinion. The main issue would be whether the jus ad bellum is relevant to assess the conduct of the ousted power in the first place. Given that occupation does not transfer sovereignty, the sovereignty remains in the hands of the (temporarily) ousted government. If the latter were to use force against the occupying power on the occupied territory would there even be a question of violation of territorial integrity and sovereignty raising issues of jus ad bellum given that it is technically using force on its own territory? The author refers to state practice that seems to suggest that such use of force by the ousted government is seen as being illegitimate but also concludes that the jus ad bellum is actually not relevant to assess this situation. What is most puzzling in the present reviewer’s opinion is that the same justification is given for the inapplicability of the jus ad bellum for the assessment of the use of force by the occupying power and against the occupying power. Indeed, the author states that “the occupying power and the occupied state cannot rely on self-defence and jus ad bellum for the reason that they are already involved in an armed conflict. Even if the actual hostilities have diminished down, the situation of occupation inherently preserves the existence of an armed conflict in the occupied territory, making the rules of jus ad bellum irrelevant” (p. 126). Whilst this is definitely a way of explaining inapplicability of jus ad bellum in relation to the use of force by the occupying power since it is based on the strict separation between jus ad bellum and jus in bello, the present reviewer still fails to see how there would be a jus ad bellum implication in relation to the occupied power when the latter is acting against the occupying power on its own territory. Given that the two situations are not that similar, a differentiated approach, or at least a reflection on whether the use of force by the ousted government on its own territory would actually trigger the jus ad bellum framework in se, would have been a welcomed addition. Finally, there is one additional issue relating to the jus ad bellum, which might have also been interesting to look at in this part. There is currently quite some discussion surrounding what some have referred to as ‘de facto annexation’ on the basis of the protracted character of for example the occupation of the Palestinian territories. In other words, some have looked at the question whether an enduring occupation might in certain circumstances in fact be equated to annexation.

Chapters 4 and 5 deal more particularly with the use of force in the occupied territory from an IHL perspective. Two main issues are being dealt with here: first, the question of the legitimacy of armed resistance against the occupying power and second, the tension between the law enforcement and conduct of hostilities models in the occupied territory.

Concerning the question of the legitimacy of armed resistance against the occupying power (chapter 4), the author emphasizes that whereas for a long time diverging views on the issue have barred codification of any rules be it in favour or against armed resistance, IHL has evolved in a way that it nowadays acknowledges the existence of armed resistance in the occupied territory. IHL does not prohibit such armed resistance but does not provide a right to participate in such resistance either. Without recognizing an explicit right to participate in such resistance, by granting certain rights to those participating in such armed resistance movements, such as the POW status under certain circumstances, IHL does seem to support the legitimacy of such an armed resistance. Similarly, it is now generally admitted that there is no such thing as the existence of a duty of obedience of the population of the occupied territory. The author also brings in the right to self-determination as further evidence of support for the legitimacy of such resistance.

Concerning the tension between law enforcement and conduct of hostilities in occupied territories (chapter 6), this is indeed, as the author already identified at the beginning of his book, one of the major challenges raised by recent examples of occupation. The author promises a novel perspective on the interplay between the two paradigms (p. 165). Under article 43HR the occupying has the obligation to restore and ensure public order and safety. The relevant paradigm regulating the use of force here is, as would be the case for the obligation to ensure public order in a domestic context, the law enforcement one. However, occupation being hostile in nature, it might occur that hostilities resurface in the occupied territory. Use of force in that framework will be regulated by the conduct of hostilities paradigm, hence by resorting to means and methods of warfare. Both paradigms might thus co-exist in situations of occupation and that is exactly the issue that is being addressed in chapter 5 of the book under consideration. The main difficulty generated by such potential co-existence is to determine whether a specific event actually warrants a response under the law enforcement or conduct of hostilities paradigm. The author provides an overview of different ways this question has been addressed in academic literature. One of the suggestions that has often been made is to draw an analogy with the threshold established for a non-international armed conflict to exist (NB it concerns really an analogy here given that situations of occupation are always classified as international armed conflicts). Basically this means that when a particular confrontation reaches the threshold of a non-international armed conflict, it allows the occupying power to use force under the conduct of hostilities model. Every confrontation below that threshold should be addressed through law enforcement. The author reaches a similar solution but by framing it slightly differently. He indeed states that this solution does not rely on an analogical application of the NIAC threshold but rather is a consequence of the principle of continuity between the means at the disposal of the ousted sovereign and those allowed to the occupying power (p. 236). This means that if the ousted sovereign in a similar situation would respond by using force under one model or the other, this is also the way in which the occupying power should act. This is definitely an interesting way of looking at, even if ultimately the solution is very similar to the one that would be achieved by applying the analogy with the threshold triggering a NIAC. This is logical given that the existence or not of armed confrontations reaching the threshold of a NIAC also guides the conduct of a legitimate sovereign in its own territory.

The last chapter, chapter 6, directly builds further upon the previous chapter given that it assesses the regulation of the use of armed force in occupied territory in light of the right to life. Indeed when the occupying power is using force under the law enforcement paradigm the relevant applicable body of law is international and domestic human rights law, including the right to life. Under the law enforcement paradigm, the use of lethal force is allowed only as a last resort measure when there is no other alternative way to protect a legal interest of the same value. This is of course in strong contrast with the use of lethal force under IHL in the framework of the conduct of hostilities paradigm. This question is ultimately a more specific illustration of the question relating to the relationship between IHL and IHRL in situations of armed conflict.

As a conclusion, the author argues that the legal framework regulating the use of force in occupied territory is actually rather clear but that the main challenge lies in the implementation of said framework. Whereas the present reviewer would agree that there are definitely important issues of enforcement, there are also still some grey areas, which might render the strict abiding to the framework not as easy as the author might suggest. Similarly to the fact that it is not always clear when internal disturbances have reached the threshold of a NIAC, it is not always easy to determine on the ground whether a particular event in a situation of occupation would actually warrant a response under the law enforcement or conduct of hostilities paradigm. Whereas the present reviewer does agree with the author that the presumption should be in favour of the law enforcement model, the realities of war (which do continue to exist even in rather calm situations of occupation) should also be taken into account when actually assessing the conduct of the occupying power. In essence, even if an analogy with the powers of the regular governmental authority can be made, occupation does remain an armed conflict situation even in its ‘calmer’ moments, which is not the case of potential internal disturbances faced by the legitimate authority and hence the situation of the occupying power is slightly more difficult by the very nature of the construction that is occupation.