Hunting the October 7 Attackers: What the Law of Armed Conflict Permits – and What It Doesnt

In a May 20 story, the Wall Street Journal reported on an Israeli “high-tech campaign to kill or capture every Oct. 7 attacker.†According to the Journal, an Israeli task force, reportedly known as NILI, has identified and killed hundreds of those involved in the horrific October 2023 massacre that left about 1,200 Israelis dead. The Israel Defense Forces (IDF) and Shin Bet apparently use captured videos, facial recognition, intercepted communications, location data, and other intelligence to identify, locate, and capture or kill them. 

The targets range from an individual who drove a tractor through the border fence, paving the way for the invasion of Hamas ground forces into Israel, to senior Hamas leaders, such as Ezzedin al-Haddad. He had risen to become head of the al-Qassam Brigades as the IDF serially killed his predecessors and was reportedly rebuilding Hamas's military capability. And, on May 26, the IDF killed his successor, Mohammed Odeh, who was involved in the planning of the Oct. 7 massacre. In addition to those being killed, hundreds of Gazans are awaiting trial in Israel for their participation in the attacks, and this month, the Israeli Parliament passed legislation establishing a special military tribunal to try them. The fact that they are in custody awaiting trial underscores the distinction between criminal accountability and targetability, separate legal issues governed by separate bodies of law.

Following the May 15 strike on al-Haddad, Lieutenant General Eyal Zamir, the IDF's Chief of Staff, warned, “The IDF will continue to pursue our enemies, strike them and hold accountable everyone who took part in the October 7th massacre.†Defense Minister Israel Katz similarly announced after Odeh's death, “We pledged to eliminate everyone who led the October 7 massacre, and that is what we will do,†Katz wrote. “They are all marked for death, everywhere.†Unsurprisingly, Hamas has labeled the campaign “nothing but an extension of the policy of extrajudicial executions and systematic killing that Israel has practiced against the Palestinian people for decades.â€

Public debate in Israel has for some time focused on the legal basis for targeting those who participated in the Oct. 7 attacks. Media reports (e.g., here and here) asserted that the IDF's International Law Division took the position that lethal force under the law of armed conflict (LOAC) is “preventive†rather than “punitive,†and therefore cannot be based solely on an individual's past participation in the Oct. 7 attacks. Reportedly, in at least some instances, attacks against individuals who participated in the massacre were disapproved on this basis, which sparked controversy. An IDF Spokesperson seemingly rejected the claims, albeit with vague language, stating, “The policy is to act against all participants in the massacre, regardless of their membership in a terrorist organization. To this end, an orderly operational process is carried out in accordance with international law.â€Â Â 

Although Israel's policy regarding the Oct. 7 perpetrators also extends to capturing, detaining, and ultimately trying them, in this article, we examine the legal issues raised solely by the lethal operations under the law of armed conflict (LOAC). Our inquiry focuses on who, when, and how those involved in the Oct. 7 massacre may be attacked pursuant to the so-called “conduct of hostilities†rules. Without access to the intelligence underpinning individual attacks, it is, of course, difficult to draw definitive conclusions; therefore, we will set out the conditions that would underpin such determinations. While many of the attacks are almost certainly lawful, some may be unlawful if the facts are as reported in the Wall Street Journal article. 

A note on the general legal framework for any analysis of lethal force: Although our discussion is limited to LOAC, we remind readers that unlawful killing under that body of law is also a war crime, murder under the domestic law of States with adjudicative jurisdiction, an extrajudicial killing under international human rights law, and, in some instances, a crime against humanity.

The Applicable Law

That an armed conflict is underway is evident from the continued acts of violence between the belligerents and the real risk of resumption of armed confrontations. This is especially the case given Hamas's failure to demobilize, dissolve, or suffer complete military defeat and instead remain in control of significant territory. Accordingly, the Israeli attacks are governed by LOAC. 

That said, the classification of conflict in Gaza remains contested. The hostilities between Israel and organized armed groups in Gaza, principally Hamas and Palestinian Islamic Jihad, constitute at least a non-international armed conflict. At the same time, certain rules traditionally associated with international armed conflict–most notably those governing occupation and blockade–are often invoked in relation to Gaza by international bodies and, in some contexts, by Israel itself. Indeed, some schools of thought maintain that the armed confrontations involve an international armed conflict and an occupation under the Fourth Geneva Convention. For present purposes, little turns on these issues. The core conduct of hostilities rules relevant here–distinction, proportionality, and precautions in attack–apply in materially similar form in both international and non-international armed conflict.

In that regard, we note that Israel is not a Party to the 1977 Additional Protocol I, which contains the key treaty-based “conduct of hostilities†rules for international armed conflict. However, as indicated in the ICRC study on Customary International Humanitarian Law, with some nuances, those rules generally reflect customary law applicable in both international and non-international armed conflict.

It is also essential to understand that the LOAC targeting rules apply to the Israeli campaign against the Oct. 7 attackers even though there has been a ceasefire between Israel and Hamas since October 2025 (ICRC 2025 Commentaries, common art. 3, para 564 (“[A]rmed confrontations sometimes continue well beyond the conclusion or unilateral pronouncement of a formal act such as a ceasefire, armistice or peace agreement. Relying solely on the existence of such agreements to determine the end of a non-international armed conflict could therefore lead to a premature end of the applicability of international humanitarian law in situations when, in fact, a conflict continues.â€). A ceasefire, standing alone, is but a temporary suspension of hostilities (Hague Regulations, art. 36; see also here). In this regard, the ceasefire agreement provides, “All military operations, including aerial and artillery bombardment and targeting operations, will be suspended.†But from a LOAC perspective, the mere fact that an attack might have breached a ceasefire term is irrelevant for our purposes; it does not render an otherwise lawful attack under LOAC unlawful. Whether the attack breaches a LOAC obligation depends instead on who was targeted and how.

Lawful Targets

Before turning to who may be targeted in the campaign, it is essential to dispel one red herring. Revenge, retribution, or retaliation cannot provide the legal basis for an attack. Public statements and the reported prioritization of targets whose deaths may console victims' families make motive relevant to how the campaign is perceived. But motive is not the legal test. The question is whether the individual is targetable at the time of attack and whether the attack otherwise complies with LOAC limitations on how and when an attack may be mounted. 

During an armed conflict, it is permissible to attack members of the enemy armed forces and civilians who are directly participating in hostilities for such time as they are participating (Customary IHL study, Rules 1, 4, 6). The Israeli campaign implicates both categories.

Those involved in the Oct. 7 attacks are neither “combatants†nor members of “dissident armed forces,†well-known categories of targetable individuals in international and non-international armed conflict, respectively. However, under international law applicable to both types of armed conflict, “organized armed groups†are also treated as “armed forces†for targeting purposes, and their members may be attacked while serving in that group (DoD Law of War Manual, § 5.7.1; Customary IHL study, Rule 4; Interpretive Guidance, page 32; AP I, art. 43). 

When a group consists of both fighting and non-fighting components, only the former qualify as an organized armed group. Thus, in this case, membership in Hamas does not, on its own, render an individual targetable. Rather, only those who are members of the fighting component (the “overall organized armed groupâ€) and leaders who exercise control over both the fighting and non-fighting functions of Hamas are targetable on the former basis. In Hamas, the overall organized armed group comprises its fighting wing, the al-Qassam Brigades, and other sub-organizations that are directly involved in Hamas's military operations, but not, for instance, those elements of the organization that provide social services. Palestinian Islamic Jihad may be easier to characterize as an organized armed group in its entirety, at least to the extent it has no meaningful non-military component. The key point is that individuals may be targeted based on their “status†as members of an organized armed group, rather than on their individual conduct at the time of the attack. 

An open question is whether all members of the group may be attacked. The U.S. position, with which Mike agrees, is that “[l]ike members of an enemy State's armed forces, individuals who are formally or functionally part of a non-State armed group that is engaged in hostilities may be made the object of attack because they likewise share in their group's hostile intent†(DoD Law of War Manual, § 5.7.3). 

By contrast, the ICRC has argued that only group members who have a “continuous combat functionâ€â€“ like serving in a combat role, gathering intelligence actionable at the tactical level of war, or transporting ammunition to active fighting positions on the front line– are targetable based on their membership. The ICRC explains that the criterion “distinguishes members of the organized fighting forces of a non-State party from civilians who directly participate in hostilities on a merely spontaneous, sporadic, or unorganized basis, or who assume exclusively political, administrative or other non-combat functions (Interpretive Guidance, page 34). Critics view the approach as impractical and imbalanced, especially in unconventional warfare, since members without a continuous combat function may not be attacked on the basis of membership, whereas their counterparts in the regular armed forces performing the same functions may be (see, e.g., Watkin). But its proponents respond that the State does not need to rely on members of its armed forces for non-combat roles, and the decision to make them members of the armed forces comes with its own tradeoffs.

Much has been written about the controversy, but for our purposes, suffice it to say that, at least,  any current member of Hamas's overall organized armed group or Islamic Jihad whose role in the organization is related to the conduct of hostilities is targetable around the clock. This would be true whether or not an individual participated in the Oct. 7 massacre or what their role was in that attack. 

But it must be cautioned that the mere fact that individuals participated in the attacks while they were members of an organized armed group has not, as such, rendered them targetable now. They must be members at the time they are killed; once they have left an organized armed group, their targetability depends on whether they are directly participating in hostilities at the time of an Israeli lethal operation against them, that is, the second basis for attacking them.

Under LOAC, a civilian who is not a member of an organized armed group (or does not have a continuous combat function under the ICRC interpretation) may be attacked if “directly participating in the hostilities,†a standard that applies equally in both international and non-international armed conflict (Customary IHL study, Rule 6; AP I, art. 51.3; AP II, art. 13.3) Unlike members of organized armed groups, however, direct participants may be targeted only “for such time†as they are so participating. The two central issues surrounding direct participation are, therefore, which actions qualify as direct participation and the scope of the “for such time†limitation.

In its Interpretive Guidance on direct participation, the ICRC has identified three constitutive elements that qualify an act as direct participation. Although there is some controversy over their application in concrete situations, these elements are generally considered an accurate characterization of the law (page 46).

1. the act must be likely to adversely affect the military operations or military capacity of a party to an armed conflict or, alternatively, to inflict death, injury, or destruction on persons or objects protected against direct attack (threshold of harm), and
2. there must be a direct causal link between the act and the harm likely to result either from that act, or from a coordinated military operation of which that act constitutes an integral part (direct causation), and 
3. the act must be specifically designed to directly cause the required threshold of harm in support of a party to the conflict and to the detriment of another (belligerent nexus).

We view the ICRC's three-element framework as a useful and generally accurate synthesis of existing law, while recognizing that reasonable disagreement persists over whether these elements reflect the correct interpretation of the law in the first place. Notwithstanding those debates, there is universal agreement on the rule itself.

Most of the controversy regarding the rule's actual application centers on the causation element, specifically whether certain acts constitute direct participation that opens the door to an attack, or merely indirect participation. For instance, there is disagreement over whether those who merely build weapons that are subsequently used by others qualify as targetable direct participants. 

There is no question that almost every act directly associated with the Oct. 7 attacks qualifies as direct participation in the hostilities and would have rendered all those individuals who were not members of organized armed groups targetable while the attack was unfolding. However, targetability based on direct participation is subject to a time constraint; it is available only “for such time†as the participation is underway. 

The scope of the for such time limitation has been the subject of significant disagreement. The ICRC takes the narrow view that the period of targetability is limited to “measures preparatory to the execution of a specific act of direct participation in hostilities, as well as the deployment to and the return from the location of its execution†(Interpretive Guidance, page 65). The late Yoram Dinstein took a broader view, according to which, “it is necessary to go as far as is reasonably required both ‘upstream' and ‘downstream' from the actual engagement†to determine the relevant time span during which an attack is permitted. (Conduct of Hostilities, page 201; see also Boothby). Some States, including the United States, have articulated positions that align somewhere in between, emphasizing that civilians who repeatedly take a direct part in hostilities may be targetable for the duration of their participation and that the temporal window is informed by an unbroken chain of causation between the preparatory, execution, and return phases of specific hostile acts (see, e.g., DoD Law of War Manual, § 5.8.4).

Of particular relevance vis-à-vis the Israeli campaign is the Israeli Supreme Court Targeted Killings case, which guides the IDF at least as a matter of domestic Israeli law. There, the court reviewed IDF targeting operations through the lens of LOAC, including the rule relating to the loss of protection by civilians directly participating in the hostilities. In doing so, the court tackled the “for such time†limitation and, while admitting that this question calls for a case-by-case approach, made a distinction between two situations (¶ 40): 

On the one hand, a civilian who takes a direct part in hostilities on a single occasion or sporadically, but has severed his connection with them (whether entirely or for a lengthy period), should not be attacked. On the other hand, we must avoid a phenomenon of the revolving door, whereby every terrorist may invoke sanctuary or claim refuge while he is resting and making preparations, so that he has protection from being attacked.

Notably, following the court's decision, the ICRC's continuing combat function test may be seen as an attempt to address the second category; it's unclear how the court would have decided these issues with the benefit of the status-based targeting category that the ICRC's framework allows.

All that said, there is no question that the participants in the Oct. 7 attacks were fully targetable as they prepared to carry them out, while they were underway, and as they returned to Gaza, even if they were not members of an organized armed group. However, even under Dinstein's more relaxed interpretation of “for such time,†the vast majority of those who directly participated in the Oct. 7 attacks would not remain targetable today on that basis alone. Unless they are current members of an organized armed group or are otherwise presently engaged in acts amounting to direct participation in hostilities, their past participation, in and of itself, does not render them targetable. Such perpetrators would fall within the first category of examples given by the Israeli Supreme Court. 

It must be cautioned, however, that past participation nevertheless matters with respect to membership in an organized armed group and direct participation. Such participation can support, as an evidentiary matter, the conclusion that an individual is still a member of an organized armed group. It may also be relevant to assessing whether the individual is planning or preparing attacks. But neither proposition collapses the distinction between indicia of targetability and targetability itself.

Limitations on Attacks

Obviously, the IDF must adequately verify the status of those it attacks in this campaign. The reported reliance on facial recognition, intercepted communications, and location data also underscores this obligation. The issue is not whether advanced technology, including artificial intelligence, may be used; it may. Rather, it is whether the information available at the time, assessed in good faith and considering the system's limitations, reasonably establishes that the individual is a lawful target (Targeting Killings case, ¶ 40; DoD Law of War Manual, § 5.4.3.2). 

This conclusion is not defeated merely because some doubt remains. Targeting law does not require certainty. As the DoD Law of War Manual explains, commanders and other decision-makers “must presume that persons or objects are protected from being made the object of attack unless the information available at the time indicates that the persons or objects are military objectives,†with that presumption serving as the starting point for the exercise of good-faith military judgment (§ 5.4.3.2). Thus, residual uncertainty does not preclude attack when the available intelligence reasonably establishes current membership in an organized armed group or direct participation in hostilities. Doubt only becomes legally decisive when the evidence does not reach that threshold; where the intelligence does not reliably establish current membership in an organized armed group or direct participation at the time of the lethal operation, the individual may not be attacked merely because they appear on an Oct. 7 list. 

Even if the individuals who participated in the Oct. 7 attacks qualify as members of an organized armed group or as direct participants at the time they are attacked, the strike must comply with the rule of proportionality and the requirement to take precautions in attack. The former prohibits  “[l]aunching an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated†(Customary IHL study, Rule 14; AP I, arts. 51(5)(b) and 57(2)(a)(iii); DoD Law of War Manual, § 5.10). Accordingly, when planning an attack, the IDF is obligated to assess the likely collateral damage to civilian objects or incidental injury to civilians to ensure it is not excessive to the military advantage generated by killing the target. For instance, the al-Haddad strike, in which 13 bombs were dropped on an apartment and a car trying to leave, also killed his wife, daughter, and several other civilians. Those whom the IDF expected to harm when executing that strike would have had to be factored into the proportionality assessment under the law.

The essential point regarding the campaign is that the advantage must, as noted by Dinstein, “be military and not purely political†(page 122; see also ICRC Commentary to AP I, ¶¶ 2207-09). This being so, it is appropriate for the IDF to consider, for instance, how killing a lawfully targetable individual who participated in the Oct. 7 attacks will affect Hamas's current or future military operations or capabilities. By contrast, general deterrence, public reassurance, or the satisfaction of retribution is too diffuse or otherwise beyond the bounds to be weighed as the concrete and direct military advantage anticipated from a particular attack. (DoD Law of War Manual, § 5.12.2). As the ICRC Commentary to Article 57 of Additional Protocol I explains, “The expression ‘concrete and direct' was intended to show that the advantage concerned should be substantial and relatively close, and that advantages which are hardly perceptible and those which would only appear in the long term should be disregarded… A military advantage can only consist in ground gained and in annihilating or weakening the enemy armed forces.†(¶¶ 2209 and 2218).

Such attacks must also comply with the requirement to take precautions in attack (Customary IHL study, Rule 15; DoD Law of War Manual, § 5.11; AP I, art. 57) This requires that they be planned, approved, and executed in a manner that poses the least risk of harm to civilians and civilian objects, so long as no military advantage is sacrificed to minimize civilian harm. In the context of the Israeli campaign, for instance, it would be unlawful to conduct an operation against lawful targets, but that is designed to send a message to those in Gaza, if doing so would present a greater risk to civilians and civilian objects than alternative means of killing the individuals.

Concluding Thoughts

The key legal point is straightforward. Participation in the Oct. 7 attacks did not place every participant indefinitely beyond the protection of the law of armed conflict. Under LOAC, individuals may be targeted because they are current members of an organized armed group or because they are presently directly participating in hostilities. But absent one of those bases for targetability, past participation alone does not suffice. And, indeed, past participation in the Oct. 7 massacre would not be necessary either. 

This does not mean many of the reported Israeli operations are unlawful. Al-Qassam Brigade, other Hamas entities that regularly support its military operations, or Islamic Jihad operatives are lawful military objectives regardless of their role on Oct. 7. Likewise, individuals who participated in the attacks and are currently directly supporting or conducting attacks may be targeted. This is so even if a motive for the strikes is retribution for their past conduct. But that cannot be the sole purpose or legal basis. Ultimately, the legality of the campaign under LOAC turns not on the horror of the attacks the people of Israel suffered, which is unquestionable, but on the status and activities of those targeted at the time force is used against them.

 

FEATURED IMAGE: Head of the Shin Bet domestic security service Major General David Zini (L) speaks with Israel’s army chief Lieutenant General Eyal Zamir as they wait for a speech by US President Donald Trump at the Israeli parliament, the Knesset, in Jerusalem on October 13, 2025 (Photo by Saul Loeb/Pool/AFP via Getty Images)