The Nature and Implications of Israeli Occupation of the Palestinian Territory: Part II

[Captain Peter S. Konchak is a Judge Advocate in the United States Army who is currently assigned to the Office of the Staff Judge Advocate for III Armored Corps and Fort Cavazos, and whose academic work is focused on matters of national security law and policy]

The views expressed in this article are those of the author and do not represent the Department of Defense, the Department of the Army, or any other entity or agency of the U.S. government.

Introduction

Part I of this article demonstrated that the formal application of belligerent occupation norms to Israel’s military presence in the Palestinian Territory is predicated upon Israel’s implicit recognition of that entity as a belligerent community with which it is engaged in an ongoing international armed conflict (IAC). This Part explains that this conclusion has significant implications for Israel’s jus ad bellum obligations towards the Palestinian Territory.

The existence of an ongoing Israeli-Palestinian IAC is central to explaining the ICJ’s recent conclusion that the Israeli occupation implicates the jus ad bellum as a use of force, despite continued ambiguity as to whether the Palestinian Territory constitutes a state. Moreover, three further legal conclusions flow from the identification of an ongoing Israeli-Palestinian IAC.

First, the jus ad bellum is broadly applicable to all Israeli military action in or against the Palestinian Territory, beyond those involved in the occupation itself. Second, the jus ad bellum legality of those actions must be assessed in the framework of a latent armed conflict that has not yet been settled by a peace agreement. Third and finally, the ultimate jus ad bellum legality of Israel’s ongoing occupation of the Palestinian Territory must be determined by reference to the lawfulness of Israel’s initial resort to force in its ongoing IAC with the Palestinians.

Application of the Use of Force Prohibition

As Judges Nolte and Cleveland explained in their separate declaration to the ICJ’s occupation advisory opinion, a belligerent occupation constitutes “an ongoing use of force,” and therefore its legality “is determined by the international rules regarding the use of force in foreign territory”—the jus ad bellum. In and of themselves, those propositions are incontestable. However, as Professor Marko Milanovic suggests, their application to the Palestinian Territory is uncertain absent further explication of the juridical status of that territory.

While the modern jus ad bellum broadly prohibits the interstate use of armed force, states are generally at liberty to employ force against a non-state actor (NSA). This framework makes it unclear whether the jus ad bellum applies to Israel’s use of armed force in or against the Palestinian Territory.

The conclusion that the Palestinian Territory clearly constitutes, at the very least, a recognized belligerent community engaged in an IAC with Israel, resolves that ambiguity.

The recognition of an NSA as a belligerent community in an ongoing NIAC—and the consequent treatment of those hostilities as the functional equivalent of an IAC under the jus in bello—also results in the application of jus ad bellum norms to the conflict. This is most apparent with respect to the treatment of third-party intervention in the hostilities.

Prior to the recognition of an NSA as a belligerent, third state participation in a NIAC against that NSA does not necessarily implicate the jus ad bellum. Since NSAs do not generally enjoy protections under the jus ad bellum, the employment of armed force against a non-state party to a NIAC cannot, as a definitional matter, constitute a “use of force” against that entity.

Once an NSA is recognized as a belligerent community, however, the neutrality rules applicable to an IAC come into effect. Accordingly, third states enter an ongoing IAC against a recognized belligerent if they engage in hostilities against that entity to a significant extent. Such involvement constitutes a “resort to armed force” by the intervening state against that belligerent community, the legality of which can be assessed under the jus ad bellum.

The predominant view appears to be that the jus ad bellum strictly prohibits third states from engaging in hostilities against either the recognized belligerent community or the existing state party to the conflict. (Dinstein, Non-International Armed Conflicts in International Law, 2nd ed., p.144). Under this view, the conduct of hostilities against a recognized belligerent community by a third state would therefore constitute an illegal use of force by that third state against that belligerent. Logically, this is possible only if that recognized belligerent community possesses rights and obligations under the jus ad bellum that it did not have prior to the point of recognition.

A contrary position holds that the jus ad bellum permits forcible intervention by third states against either party to an IAC between a state and a belligerent community. Even under this view, however, the jus ad bellum regulates the use of force between third states and a recognized belligerent. By permitting third state participation in hostilities on behalf of the non-state party to the conflict, this doctrine establishes an exception to the use of force prohibition that otherwise applies to third states in an ongoing armed conflict between a state and an NSA.

In a NIAC, forcible intervention by a third state against the existing state party to the conflict constitutes an unlawful use of force by the intervenor. If such a use of force becomes lawful when the NSA is recognized as a belligerent community, the implication is that the non-state party has acquired jus ad bellum authorities vis-à-vis the exiting state party to the conflict. In other words, by virtue of its recognition as a belligerent community, the NSA acquires the jus ad bellum authority to receive support that involves the use of armed force against a sovereign state.

Regardless of which doctrine is accurate, therefore, the legality of a third state’s use of armed force against a recognized belligerent community in an ongoing armed conflict is governed by the international law norms that regulate the interstate use of force. Critically, this is due to the fact that once recognized as a belligerent community, the NSA is afforded rights and obligations under the jus ad bellum that normally only apply to fully recognized sovereign states.

This demonstrates that when hostilities between a state and an NSA constitute an IAC under the recognition of belligerency doctrine, the jus ad bellum provides the appropriate legal framework for assessing the legality of actions involving the ongoing use of armed force between the parties to the conflict.

Jus Ad Bellum Implications Beyond Occupation

Three critical legal implications flow from the foregoing conclusions regarding the doctrinal basis of the Israeli occupation of the Palestinian Territory under the jus in bello and its status as an ongoing use of armed force by Israel under the jus ad bellum.

First, the general applicability of the jus ad bellum to issues involving the employment of armed force between Israel and the Palestinian Territory means that the legality of all Israeli military activities in or against the Palestinian Territory—not only those relating to its effective control of that entity—can be evaluated under the jus ad bellum as a use of force against that entity.

A comprehensive list of the myriad actions that may be subject to such an analysis is well beyond the scope of this article. But this would include, for instance, the jus ad bellum legality of Israeli military activities in the Palestinian Territory that are carried out without the consent of the officially recognized Palestinian authorities.

In its ongoing NIAC with Hamas, Israeli is employing armed force against an entity that is unaffiliated with the legitimate Palestinian authorities. However, this use of force is occurring within the territorial jurisdiction of the Palestinian Territory. If the Palestinian Territory possesses jus ad bellum rights vis-à-vis Israel, then those Israeli military activities prima facie constitute a use of force against that entity—a trans-border projection of armed force by Israel into the Palestinian Territory. Absent consent from the official Palestinian authorities to execute those actions, such activities might violate the use of force prohibition. Alternatively, Israel’s actions in the Gaza Strip may constitute a lawful measure of self-defense amid the inability or unwillingness of the legitimate Palestinian authorities to eliminate the threat to Israel posed by Hamas.

Second, the foregoing conclusions also make clear that questions regarding the jus ad bellum legality of ongoing or future Israeli military activities in or against the Palestinian Territory must be assessed in the context of an ongoing—albeit latent—Israeli-Palestinian IAC.

During an ongoing IAC, the use of armed force by one party to the conflict against an enemy belligerent is governed by a legal framework that differs from the “peacetime” jus ad bellum. (Kenneth Watkin, Fighting at the Legal Boundaries, p.58). This paradigm is comprised of interrelated jus ad bellum and jus in bello norms that may significantly alter opposing belligerents’ authority to employ armed force against each other relative to what is permissible in a peacetime context. One such situation is where the opposing parties have suspended active hostilities against each other pursuant to a ceasefire agreement. In those circumstances, the terms of the ceasefire—and not the general use of force prohibition—regulate the opposing belligerents’ authority to employ armed force against each other.

Accordingly, the 2005 ceasefire that ended the Second Intifada may continue to govern the legality of hostile actions by Israel against the Palestinian Territory—those conducted against organized armed groups operating under the authority of the internationally-recognized Palestinian authorities. This agreement was implicitly affirmed by the parties as recently as March 2023, when Israel and the PA concluded an agreement in which they “reaffirmed their commitment to all previous agreements between them.”

The 2005 ceasefire constitutes, at the very least, an appropriate starting point for assessing the jus ad bellum legality of any ongoing or future use of force between Israel and the Palestinian Territory. For example, the ceasefire arguably regulates recent Israeli military actions against militants belonging to the Fatah party—an element of the PLO and the PA—in the West Bank. The resumption of major active hostilities by Israel or the legitimate Palestinian authorities against the other would be lawful only if the opposing party committed a “serious violation” of that ceasefire. Under the terms of that agreement, such a violation would have to involve one party reinitiating large-scale hostilities against the other. Importantly, however, the ceasefire does not preclude Israel from continuing to exercise effective control over part or all of the Palestinian Territory.

Third and finally, the doctrinal basis of the Israeli occupation of the Palestinian Territory likewise indicates that—perhaps contrary to the ICJ’s ultimate holding in its advisory opinion—the jus ad bellum legality of that occupation must be assessed in the context of the complex, ongoing armed conflict in which that occupation arose and in which it persists.

As the ICJ stated in that opinion, the legality of a use of force under the jus ad bellum must be assessed both in terms of the lawfulness of the initial resort to force as well as the legality of the continued employment of armed force. Accordingly, the myriad doctrinal transformations of the hostilities between Israel, Egypt, Jordan, and the Palestinians potentially bear upon the ultimate legality of Israel’s current occupation of the Palestinian Territory. This is true for at least two reasons.

First, while the ICJ did not assess the jus ad bellum legality of Israel’s initial resort to armed force against Egypt and Syria in 1967, that issue determines whether Israel’s occupation could ever be deemed lawful, as that was the context in which the occupation first arose. If the onset of the occupation in 1967 was not a lawful measure of self-defense, then there is no situation in which the occupation could ever be deemed lawful under the jus ad bellum. By contrast, however, if the onset of the occupation was originally justified as part of a defensive response by Israel to Egyptian and Jordanian aggression, then the legality of the occupation depends entirely upon the issue the ICJ did address—its jus ad bellum legality as an ongoing employment of armed force.

Second, in view of the foregoing point, the changing legal character of the hostilities in the Palestinian Territory between 1967 and the present—the termination of the Israeli-Jordanian and Israeli-Egyptian IACs, the emergence of an Israeli-Palestinian IAC, and the course of the Israeli-Palestinian hostilities since 1994—is relevant to determining whether the continuation of Israel’s occupation constitutes a legal use of force as a measure of self-defense. This is because the jus ad bellum legality of an ongoing use of force during an ongoing armed conflict is determined by reference to the principles of necessity and proportionality. Those principles, in turn, are informed by an assessment of the legitimate war aims that the defending state may pursue in self-defense. And those legitimate objectives are determined in significant part by the nature of the threat faced by the defending state as it initiates and continues to prosecute its forcible defensive response.

For instance, armed aggression that generates a “full-scale war” may entitle the defending state to effectuate the total military defeat of the aggressor and potentially even topple its government. When such extensive aims may lawfully be the object of self-defense, the comprehensive use of armed force—such as the prolonged occupation of the aggressor state’s territory—may constitute a proportionate measure of self-defense under the jus ad bellum.

In the context of the Israeli-Palestinian IAC, the salience of this point is obvious if considered in concrete terms. Understood exclusively in reference to its origins in the Six Day War, Israel’s present occupation of the Palestinian Territory is difficult to justify as a proportionate measure of self-defense. Any legitimate war aims that Israel may have been authorized to pursue vis-à-vis Jordan and Egypt in 1967 were resolved by the peace agreements between Israel and those states. At least by 1994, therefore, it is doubtful that continued Israeli effective control of the Palestinian Territory could be justified as a legitimate measure of self-defense pursuant to the onset of those hostilities.

Importantly, however, it is far more plausible that the Israeli move to fully reoccupy the Palestinian territory amid the Second Intifada—after initially pursuing limited disengagement under the Oslo Accords—constituted a permissible defensive response pursuant to the objective of terminating an armed attack by the Palestinian organized armed groups operating under the responsibility of the internationally recognized Palestinian authorities. Consistent with the formulation in U.N. Security Council Resolution 242, which tied Israel’s withdrawal from territories it occupied in 1967 to “the “establishment of a just and lasting peace in the Middle East,” the persistence of the Israeli-Palestinian IAC arguably justifies Israel’s continued occupation (albeit not its de jure or de facto annexation) of the Palestinian Territory pending a peaceful resolution of that conflict.

In those circumstances, it is far more difficult to definitively conclude that the Israeli occupation, in and of itself, is an unlawful use of force under the jus ad bellum.

Conclusion

The foregoing makes clear that the doctrinal basis of Israel’s ongoing occupation of the Palestinian Territory has broad implications for the application of the jus ad bellum between those entities. The existence of an ongoing Israeli-Palestinian IAC means that the legality of Israeli hostilities in or against that entity—beyond its continuing occupation of the West Bank, the Gaza Strip, and East Jerusalem—may be assessed as a use of force by Israel against the Palestinian Territory. Determining the ultimate jus ad bellum legality of such actions will necessarily require a fact-intensive analysis of each specific case. Nevertheless, recognizing that the jus ad bellum regulates those actions is a critical starting point for resolving the present ambiguity as to the rights of the Palestinian Territory vis-à-vis Israel under the laws of war.