Warnings in Contemporary Conflict: Protective Measure or Source of Illegality?
Since the beginning of March 2026, the Israeli Defense Forces (IDF) have issued a number of evacuation orders in southern Lebanon. These orders have directed the inhabitants of villages and towns in southern Lebanon to leave their homes and move north. Others instructed residents of Beirut’s southern suburbs to evacuate. These orders call to mind similar orders issued by the IDF during its operation Iron Swords in Gaza following the attacks by Hamas on October 7, 2023.
Israel has stressed that its issuances constitute “advance warnings intended to help civilians avoid the dangers of impending attacks and military operations” that implement the obligation under International Humanitarian Law (IHL) to give an effective advance warning of attacks which may affect the civilian population. It has also insisted that these issuances should not be seen as “evacuation orders” since the IDF does not force persons to leave their homes and does not exercise authority over them.
There has, however, been much criticism of these measures taken by the IDF. Much of this criticism has focused on the requirement that an advance warning must be “effective,” and questioned whether the Israeli issuances fulfill this requirement. There has also been quite some discussion on the question whether the Israeli issuances violated the IHL prohibition against forcible displacement of civilian populations, for example, by Khan, Biggerstaff, and by Diamond and Nohle.
An aspect that has received less attention is the relationship between warnings and the prohibition of threats of violence, including acts aimed at spreading terror amongst the civilian population. Acts or threats of violence, the primary purpose of which is to spread terror among the civilian population, are prohibited under both treaty IHL and customary law. Non-governmental organizations such as Human Rights Watch and Diakonia have suggested that “warnings” by Israel in Gaza and Lebanon may violate this obligation. This has also been discussed briefly by Badreddine with respect to Israeli evacuation orders in Lebanon. This post engages in more detail with the relationship between this prohibition and the obligation to give an effective warning, using the “warnings” given by Israel as a case study.
The Obligation to Warn
The obligation to provide effective advance warning of an attack that may affect the civilian population forms part of the duty to take precautions in IHL. It is laid down in Article 57(2) of the First Additional Protocol to the Geneva Conventions (AP I). According to the ICRC customary law study, this rule is also a rule of customary international law that applies in both international and non-international armed conflicts. Warnings enable civilians to evacuate or seek shelter, thereby minimising civilian casualties and facilitating compliance with the principle of proportionality. The obligation is not absolute: no warning need be given when circumstances do not permit this.
The obligation to warn does not operate in isolation. Rather, it interacts with several rules of IHL with which it may come into tension. One of these is the prohibition of forced displacement. In addition to the prohibition of displacement, warnings may interact with the principle of distinction, the prohibition of ruses of war, rules related to human shields and the prohibition of threats of violence against civilians, as we have written elsewhere.
The Prohibition of Threats of Violence Against Civilians
IHL prohibits acts or threats of violence, the primary purpose of which is to spread terror among the civilian population. This prohibition is laid down in Article 51(2), AP I as well as in Article 13(2), AP II. According to the ICRC customary law study this rule is also a rule of customary international law that applies in both international and non-international armed conflicts.
The notion of a “threat of violence” is not limited to explicit or verbalised threats. It encompasses conduct that, in its context, conveys a credible prospect of harm and is intended or can reasonably be understood to instill fear among civilians. The prohibition is therefore concerned not only with the form of the communication, but with its purpose and effects. International jurisprudence has clarified that the decisive element is the primary purpose of the act.
ICTY case law has considered whether certain attacks constituted acts violating the prohibition; the tribunal did not rule on threats, but it stands to reason that what applies to acts also applies to threats. In this context, the ICTY in para. 136 of the Galić case emphasised that the prohibition covers acts of violence carried out with the specific intent to spread terror among civilians. This intent may be inferred from the nature of the acts, their repetition, the surrounding circumstances, and their predictable psychological impact.
The content of the warning can also play a role in establishing whether there is intent. As noted by van den Boogaard, when a warning is intentionally formulated vaguely, it may in some circumstances constitute a threat rather than a warning. This could indicate that the warning was intended to send the message that no civilian was safe anywhere, at any time of day or night.
Beyond the formal content of evacuation warnings, the broader discursive and operational environment in which they are issued is also relevant to their legal characterisation. An example is the use of dehumanising rhetoric by political and military officials. While such rhetoric does not in itself constitute a warning, it may shape how subsequent communication is perceived by the civilian population. From a legal perspective, dehumanising language is not per se prohibited under IHL. However, where it accompanies or precedes military operations affecting densely populated civilian areas, it may become relevant in assessing whether certain acts or statements amount to threats of violence within the meaning of Article 51(2), AP I. In particular, such rhetoric may reinforce the perception that harm to civilians is anticipated or accepted, thereby amplifying the psychological impact of warnings.
Distinguishing Genuine Warnings from Threats of Violence Against Civilians
The line between a warning and an act of violence or threat aimed at spreading terror can be fine. Baruch and Neuman note that statements calling for the evacuation of areas that are not genuine warnings, but are instead primarily intended to cause panic amongst civilians, can be considered to be a violation of the prohibition on threats or acts of violence, the primary purpose of which is to spread terror among the civilian population. Here, it must be recalled that a warning is by its nature not an “act of violence” but it can be a threat of such an act. Acts or statements that incidentally cause fear do not violate Article 51(2), AP I if their primary purpose is otherwise lawful, such as communicating operational information or enabling civilian protection. However, where conduct is designed to intimidate civilians, compel behaviour through fear, or exploit their vulnerability, it may fall within the scope of the prohibition.
The relationship between warnings and the prohibition of threats of violence under Article 51, AP I can be understood through three key considerations. First, an important question is if a warning relating to an attack on a legitimate military objective is excluded from constituting a prohibited threat. The ICTY in the Karadzić case held that “acts or threats of violence constituting terror … do not include legitimate attacks against combatants” (para. 460). This conclusion is shared by Logan and Coble. However, Article 51 does not distinguish between lawful and unlawful violence, which suggests that how a warning is given may still bring it within the scope of the prohibition, even if the attack that the warning applies to is lawful. This view seems to find support in the ICRC Commentary to Article 51, which states that the provision is intended to prohibit acts of violence the primary purpose of which is to spread terror among the civilian population without offering “substantial” military advantage. An object can offer sufficient military advantage to make it a lawful military objective without such advantage being “substantial.” This view also finds support in the literature (Tarasevich).
Second, a violation requires that the spreading of terror be the primary purpose of the warning. Where a warning is genuinely intended to enable civilians to protect themselves, it remains lawful, even if it induces fear. Incidental terror does not suffice; the decisive factor is whether inducing terror is the principal aim.
Third, intent to spread terror may be inferred from the circumstances, including the nature, timing, and feasibility of the warning. In particular, where civilians have no realistic possibility to act upon a warning, such as when there are no safe evacuation options, issuing a warning may become futile. If a party nevertheless issues such a warning without taking other precautionary measures, this may indicate that the warning serves not a protective function but rather is intended to spread terror. Other indicators that the intention of a warning was to spread terror are when the warning conveys the inevitability of harm or when it implies that civilians who remain will lose their protection from attack.
Particular concern arises where warnings are delivered in a coercive environment characterised by ongoing bombardment, severe humanitarian deprivation, or restrictions on movement. In such settings, civilians may have no genuine ability to act upon the warning without exposing themselves to comparable or greater risks. Where the issuing party knew, or should reasonably have known, of these constraints, the continued reliance on such warnings may indicate that their function extends beyond civilian protection.
The broader communicative environment is also relevant. Where warnings are accompanied by dehumanising rhetoric, this may reinforce their psychological impact and support an inference that their effects go beyond incidental fear. While such factors are not determinative on their own, they may form part of the overall assessment.
Ultimately, the assessment is fact-specific and must take into account the totality of the circumstances. Where a warning ceases to function as a genuine precaution and instead operates as a mechanism of intimidation or psychological pressure, it may cross the line into a prohibited threat of violence under Article 51(2) of AP I.
Warnings in Lebanon
The Israeli evacuation orders issued during the escalation of hostilities along the Israeli–Lebanese border in 2024 offer a further illustration of the tension between the obligation to give effective advance warning and the prohibition on threats or acts of violence against civilians. On 23 September 2024, the Israeli military issued warnings in Arabic instructing civilians to leave designated combat zones or areas where Hezbollah was allegedly operating and to distance themselves from buildings purportedly containing weapons prior to anticipated military operations. These warnings were followed by a series of increasingly expansive evacuation orders. On October 1, 2024, residents of more than twenty-five villages in southern Lebanon were instructed to evacuate immediately and relocate north of the Awwali River, while they were simultaneously warned against travelling south of the Litani River. Additional orders issued in the following days extended the scope of the affected areas and reiterated that remaining in place could expose civilians to danger.
Although such communications may be characterised as precautionary measures aimed at mitigating civilian harm, their legal assessment cannot be separated from the broader operational and humanitarian context. Many affected communities had already experienced months of cross-border hostilities, displacement, infrastructure damage, and disruption of essential services. The presence of non-State armed actors operating near civilian areas further complicated the feasibility of safe evacuation. Moreover, the scale of the orders shifted them towards area-wide displacement instructions rather than targeted warnings. The requirement that civilians relocate north of the Awwali River suggests that the objective was not merely to avoid specific military targets, but to clear broad operational zones.
In these circumstances, the feasibility of compliance became highly contested. Civilians receiving evacuation orders had to assess not only the risks of remaining in place, but also the practicality of displacement where transportation was limited, routes were damaged, and alternative shelter was uncertain. Where civilians are repeatedly informed that remaining in their homes will place them at serious risk of harm, the distinction between a warning intended to protect civilians and a communication perceived as conveying the consequences of non-compliance becomes increasingly difficult to sustain.
This trajectory continued into 2026, when evacuation directives reportedly expanded to cover vast areas south of the Litani River and, in May 2026, entire zones south of the Zahrani River were declared combat areas, with civilians instructed to relocate northwards over large distances. Taken together, these developments suggest a shift from geographically delimited warnings to regionalised evacuation regimes affecting entire civilian populations. In doctrinal terms, the increasing generality and coercive effect of these instructions intensifies the difficulty of distinguishing between permissible advance warnings and implicit threats of violence, where non-compliance is reasonably understood to expose civilians to imminent harm. As stated by Hen, measures affecting areas further removed from active hostilities, or framed in broader and less differentiated terms, require more specific justification grounded in military necessity and the presence of military objectives.
The broader communicative environment in Lebanon contributes to the doubts concerning the humanitarian intentions of Israeli evacuation orders. Badreddine has described statements by Israeli leaders as “growing indications that the threat of large-scale destruction directed at the South of Lebanon and Beirut is being articulated as a coercive strategy.” Israeli politicians continue to make such statements, such as Finance Minister Smotrich who recently called for “destroying 10 buildings in the suburbs of Beirut for every Hezbollah drone” that attacks Israel.
Conclusion
The interaction between the obligation to warn and the prohibition of threats of violence illustrates the complex way in which IHL rules operate simultaneously rather than in isolation. While warnings are intended to protect civilians, their legality depends not only on their formal issuance but on their practical function and effects. The Lebanon context demonstrates how, in extreme circumstances, the line between lawful warning and unlawful threat may become difficult to maintain. Where warnings are issued in conditions of severe deprivation, insecurity, and limited mobility, and where they form part of a broader environment of fear, their characterisation may shift towards those acts prohibited by IHL.
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Sara Benabbass is a Military Strategic Studies (MA) graduate from the Faculty of Military Sciences of the Netherlands Defence Academy.
Marten Zwanenburg is Professor of Military Law at the University of Amsterdam and at the Faculty of Military Sciences of the Netherlands Defence Academy. He has previously worked as a legal counsel for the ministries of Defence and Foreign Affairs of the Netherlands.
The views expressed are those of the authors, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.
Photo credit: Staff Sgt. Samuel Bendet, U.S. Air Force
