With the Israeli government recently stating that, according to its own calculations, over 65% of deaths from Israeli military operations in Gaza were civilians, time and investigations will tell whether any of that military conduct violated the Geneva Conventions. Another question, however, demands critical attention as well: Whether Israel is promoting an interpretation of international humanitarian law that undermines the Conventions’ values and subverts their rules. That might explain some of the outcomes we are seeing on the ground.

Despite couching its explanations in humanitarian law’s language of proportionality and minimization of harm, Israel has asserted a theory of justifiable conduct in war that, contrary to this body of law, elevates claims of military necessity in achieving the war’s aims over protection of civilians, particularly in a just war. The theory harks back to the influential nineteenth-century intellectual and military theorist Francis Lieber, who advanced it around the very time the first Geneva Convention was being developed. It is important to look back at that long-rejected concept of legitimate warfare and to closely trace what Israeli officials have propounded in the current conflict.

Francis Lieber: Conduct in a Just War

The foundation of the first Geneva Convention of 1864, and all its iterations since, has been the principle of humanity in the conduct in war, jus in bello, to reduce suffering of civilians, the wounded and sick, prisoners, and others not engaged in combat. The rules apply to all belligerents, irrespective of the justice of one side’s cause. Lieber, by contrast, founded his views of permissible conduct on his belief that some wars are vital to the moral progress of “civilized nations” and that freedom requires war against “barbarism and injustice.” To achieve quick victory in these essential wars, he permitted means of warfare that included massive harm to civilians.

A passionate opponent of slavery, Lieber advised commanders on legal issues arising in the early years of the American Civil War. When President Abraham Lincoln saw the need for a code of conduct for the Union Army, he appointed a commission to draft one. Lieber wrote the code even though he was the only civilian on the commission. In the spring of 1863, two months before the battle of Gettysburg, Lincoln adopted the code, and ever since it has been known as the Lieber Code.

The code recognized that warriors remain “moral beings, responsible to one another and to God,” such that military necessity does not encompass “the infliction of suffering for the sake of suffering or for revenge, nor of maiming or wounding except in fight, nor of torture to extort confessions” (Article 16). It prohibited enslavement and murder (Article 23) and outlawed cruel treatment of prisoners (Article 56). Apart from its firm rejection of gratuitous cruelty, however, it allowed massive harm against civilians and hospitals if a commander deemed it necessary to achieve a just outcome, and quickly.

Thus, the code stated that “the citizen or native of a hostile country is thus an enemy, . . . and as such is subjected to the hardships of the war” (Article 21). “The unarmed citizen is to be spared in person, property, and honor as much as the exigencies of war will admit” (Article 22, emphasis added) and “the inoffensive individual is as little disturbed in his private relations as the commander of the hostile troops can afford to grant in the overruling demands of a vigorous war” (Article 23). The code permitted starvation of the population. Hospitals were protected “only as much as the contingencies and necessities of the fight will permit” (Article 116). His approach was pithily summed up in Article 29 of the code: “The more vigorously wars are pursued, the better it is for humanity. Sharp wars are brief.”

A year later, when the mayor of Atlanta asked General William Tecumseh Sherman to rescind his order forcibly removing its citizens, especially to spare pregnant women, mothers, and children, Sherman responded that “my orders … were not designed  to meet the humanities of the case. . . our military plans make it necessary for the inhabitants to go away,” followed by burning the city and army’s ferocious march through Georgia and South Carolina. Scholars today have concluded that Sherman complied with the code as he plowed through these states, save for unauthorized private pillaging by some soldiers.

Although some aspects of the Lieber Code remain influential, after the adoption of the 1949 Conventions, and especially the Additional Protocols of 1977, Lieber’s approach to civilian protection became a relic. Contemporary law flatly rejects his notion that a just war permits latitude in inflicting harm to civilians, and the law now permits considerations of military necessity to prevail only within the specific confines of the rules. As the 1987 ICRC Commentaries to Protocol I state, “There is no implicit clause in the Conventions which would give priority to military requirements.” What’s more, it is now an axiom of international law that the body of rules determining when a war is justified — jus ad bellum and the UN Charter — is to have no effect on the application of the rules governing the conduct of hostilities.

Israeli military and political leaders never mention Lieber, but their public explanations reflect his approach to civilian harm in war and may well explain some of their conduct. They almost always begin with the justice of their cause in responding to Hamas’ horrific massacres, sexual violence, and hostage taking, and Israel’s existential need to eradiate that threat. They emphasize the need to win quickly. When asked about dropping 6,000 bombs in the first six days of the war, Marc Regev, advisor to Prime Minister Benjamin Netanyahu, responded “Hopefully, we will get it done quicker. That is one of our goals.” And when defending the IDF tactics, these military and political leaders emphasize speed and destruction over accuracy. The IDF chief military spokesperson Rear Admiral Daniel Hagari stated at the outset that “the emphasis is on damage and not on accuracy.”

The Duty of Proportionality

The theory is reflected, too, in the Israeli government’s approach to specific legal obligations. Take the all-important duty of proportionality, codified in Article 57(2)(a)(iii) of Protocol I and incorporated into customary international humanitarian law and accepted by Israel. It prohibits attacks that are “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.” As the U.S. Department of Defense’s Law of War Manual points out, the rule is challenging because it balances “unlike quantities and values.” There is no objective standard for assessing excessive harm or assessing its relation to military advantage. Nevertheless, as the ICRC Commentaries to Protocol I emphasize, “The principles of the Conventions are precisely aimed at determining where the limits lie; the principle of proportionality contributes to this.” (¶ 2206). And, indeed, the rule has been clear enough for criminal tribunals to apply it.

To fulfill the clear purpose of international humanitarian law, the balancing required in the proportionality rule must be assessed regarding the tactical advantage gained to secure each objective, such as the capture of a bridge or destruction of a command post, as opposed to strategic objectives (¶ 2207). It does not permit the overarching military advantage of winning the war, which could always outweigh excessive civilian harm and thus swallow the rule. The point is reinforced by Protocol I’s requirement that the anticipated military advantage must “concrete and direct,” that is, “substantial and relatively close,” not “long term” (¶2209)

Israel’s spokespeople, however, discuss proportionality in the context of the strategic objective of the war, to eradicate Hamas and all its infrastructure. Accomplishing that objective in view of the existential threat Hamas poses, they claim, outweighs any excessive harm to civilians. For example, Israeli Government Spokesperson Eylon Levy, who is well versed on the government’s position, told the BBC:

BBC anchor: I don’t dispute that there is an enormous tunnel network beneath Gaza. The question, which the U.N. and international human rights agencies ask, is whether it’s proportional, whether the collateral damage, I think has been, it has been huge. Come on. It has been huge. Whether that was proportional to the attempts to get at this tunnel network beneath the hospital.

Your response to that?

Israel Government Spokesperson Levy: You know, under international law, proportionality means that with each particular strike the collateral damage cannot be disproportionate to the expected military advantage. And the expected military advantage here is to destroy the terror organization that perpetrated the deadliest massacre of Jews since the Holocaust, the deadliest terror attack in world history since 9/11, retreated into the Gaza Strip with 240 hostages, and told us that it wants to do it again and again and again. So we’re doing everything that we can under international law to try to get civilians out of harm’s way. That’s why we spent so long urging people to evacuate the areas where Hamas has built its tunnels under schools, hospitals….

Levy’s response corresponds with the writing and commentary of Retired Colonel Pnina Sharvit Baruch, former director of the branch of Israel’s military that advises commanders on the law. Baruch wrote a 2-page brief entitled “The War with Hamas: Legal Basics” (Oct. 16, 2023), in which she described the military advantage for purposes of jus in bello proportionality in terms of the jus ad bellum object of the military campaign. In full, she wrote:

“According to the laws of armed conflict, even when attacking a military target, it is forbidden to attack if the collateral damage expected from the attack to civilians and civilian objects is excessive in relation to the military advantage expected from the attack. In view of the enormous threat that Hamas currently poses to Israel, the denial of its military capabilities is expected to give Israel a great security advantage. Without achieving this goal, Hamas will succeed in de facto denying Israel the exercise of its sovereignty in the areas adjacent to the border with the Gaza Strip. In light of this significant military advantage, even if many civilians in Gaza are harmed during the attacks, this is not necessarily excessive incidental damage and therefore would not be disproportionate attacks that are illegal.”*

In an interview, Baruch elaborated on the implications of Israel’s view of proportionality. Baruch argued that to end Hamas’ existential threat to Israel and the consequent need to eliminate its military capabilities, it is essential to get rid of each part of its infrastructure “in order to get to this overall outcome.” That military advantage of succeeding, she said, “is so heavy,” and “has such weight,” that even where civilian casualties are extensive, the attack is not disproportionate. According to this logic, no Israeli attack ever would be so, no matter how great the expected harm. Such a framework could well account for Israel’s destroying entire neighborhoods to attack Hamas assets and having “destroyed or damaged 45 percent of all housing units in the Gaza strip,” within the first four weeks of the war, according to the U.N.

As Ryan Goodman discussed with BBC Newshour, at the time Baruch was head of the International Law Department, the Israeli Ministry of Foreign Affairs published a legal backgrounder on proportionality in military strikes, which conflated in a very similar manner the writings of Justice Rosalyn Higgins on jus ad bellum with proportionality in bello.

As another example of official government statements, also consider the Israeli Ministry of Foreign Affairs’ legal explainer on the current war. It states: “Military advantage moreover may refer to the advantage anticipated from an operation as a whole.” (Israeli Ministry of Foreign Affairs, Hamas-Israel Conflict 2023: Key Legal Aspects, last updated on Dec. 14, 2023).**

In the present conflict, consider other official statements like spokesperson Levy’s following IDF strikes resulting in enormous civilian casualties. In the Halloween night attack on the densely populated Jabaliya refugee camp Israel dropped two 2,000 pound bombs, which could be expected to collapse tunnels and the buildings above them. Dozens of people, and perhaps over 100, were reportedly killed and more than a hundred injured in the attack.

When asked how Israel assessed proportionality in the attack, its spokesperson, Lt. Col. Jonathan Conricus, did not address the balance between the expected numbers of civilians killed and injured against the anticipated advantage gained in destroying the target. Instead, he cited only the overriding importance of achieving Israel’s strategic goal: “We are fighting a battle here to defend ourselves. We cannot allow a situation for Hamas to continue to exist after the atrocities of October 7,  and in order for us to be able to safeguard ourselves we have to be able to eradicate Hamas wherever they are, even if they are hiding in tunnels underneath populated areas.”

Indeed, that response is even closer to Lieber, because there is no proportionality in the equation. It is all about military necessity. A critic might argue that Lieber had no place for proportionality, and that the other Israeli statements do include such a balance. But when the “military advantage” side of the balance imports the overarching objective of the military campaign, as Levy and Baruch do, it ends up in the same place. Indeed, it is a result of the Lieber-like conflation of just war ends with the assessment of conduct in hostilities.

The Duty to Minimize Harm

Lieber’s approach is evident, too, in the Israeli government’s approach to the duty to “take all feasible precautions in the choice of means and methods of attack with a view to avoiding, and in any event to minimizing, incidental loss of civilian life, injury to civilians and damage to civilian objects” contained in Article, 57(2)(a)(ii). Adjusting “means and methods” to minimize harm is the critical duty. It includes choices of weapons used where civilians are present in or near a military target and how military operations are conducted. To illustrate the latter, the Commentaries cite the example of Allied forces’ bombardments on factories in German-occupied territory during World War II, which were conducted at night to avoid killing workers in those buildings (¶ 2200). The Commentaries also emphasize that “the precautions prescribed here will be of greatest importance in urban areas because such areas are most densely populated” (¶ 2190).

Israeli officials affirm and even celebrate the IDF’s commitment to minimize civilian harm despite the challenge of fighting an enemy embedded in and under civilian structures. This month, Levy said, “We believe we are setting the highest possible standards for the minimization of civilian casualties in counterterrorism operations in urban areas.” It will take investigations to learn what, if any, precautions Israel took in a particular attack, but in some cases, the evidence of lack of required precautions is public.

When pressed about what precautions it has taken in attacks, IDF spokespeople often emphasize Israel’s  warnings to civilians about an impending attack. But that is an additional, separate requirement in Article 57(2)(c) of Protocol I and is no substitute for adjusting means and methods of warfare. In the Jabaliya refugee camp attack, Lt. Col. Conricus mentioned no specific precautions, only Israel’s warnings to civilians to leave the area, and even shifted the burden of protection to Palestinians, saying, They “shouldn’t have been there. … They should have heeded the warning and left.”

In Israel’s many attacks on hospitals, too, it repeatedly alleged that hospitals are used by Hamas for military purposes. Even if those claims are confirmed, Israel was still responsible for minimizing harms to the wounded and sick in the facilities and medical staff, who all enjoy special protection under the Conventions. Despite worldwide attention to the sieges and attacks on hospitals, especially Al-Shifa Hospital, there is no indication in public statements or from on-site witnesses that the Israeli Defense Forces took the kinds of feasible steps needed to ameliorate the severe health crisis within the hospitals in the lead-up to or execution of the assault. The hospital ran out of fuel for its emergency generator, food and water were scarce, and patients were dying. The IDF’s claims to addressing the situation were to say it had medics and Arabic speakers enter with soldiers, posting a video of soldiers carrying boxes marked baby food and medical supplies, and later bringing incubators.

None of those steps addressed the catastrophic conditions for the patients and staff and the civilian harm left in the wake of these raids on hospitals. Moreover, until IDF cooperation in the safe evacuation of patients from Al-Shifa, Mike Ryan, the Emergencies Director at the World Health Organization, said that it had been “exceptionally difficult” to gain the IDF’s cooperation in safe movement of patients, which was “sub-par to say the least.” Since the Al-Shifa evacuation, the obstacles to safe evacuation continued. On December 9, WHO reported that a UN convoy in conjunction with the Palestinian Red Crescent Society, sought to deliver medical supplies to Al-Ahli Hospital but was repeatedly delayed, Palestinian medics were detained and beaten, and aid truck and ambulance were hit by bullets. By contrast, in prior conflicts in Gaza, the IDF established procedures for safe medical evacuation, albeit with major lapses.


Gaining compliance with the Geneva Conventions’ demand for civilian protection has always been a struggle. But its underlying values have not only survived but over time were incorporated in increasingly strengthened requirements. For a country that cites its commitments to the Conventions and humanitarian law and employs lawyers within the IDF to review targeting, to seek to enfeeble this body of law in the guise of obeying its dictates is dangerous for people in Gaza and in future conflicts. If accepted, it would make the law another casualty of this war. There must be a reckoning to prevent that.


* Editor’s note: After publication, the author of this quoted text informed Just Security that the text had been changed (in Hebrew and in English) in late October, days after its original publication at INSS. The text quoted in the Just Security article was still live at the INSS website at the time of publication of the Just Security article. The newer text states in full (and is available here):

“According to the laws of armed conflict, even when attacking a military target, it is forbidden to attack if the collateral damage expected from the attack to civilians and civilian objects is excessive in relation to the military advantage expected from the attack. Unless Hamas is deprived of its military capabilities, it will continue to pose an imminent threat that prevents the rebuilding of the destroyed villages and the return of citizens to their homes, thus de facto denying Israel the exercise of its sovereignty in the areas adjacent to the border with the Gaza Strip. In view of the enormous threat that Hamas currently poses to Israel, the denial of its military capabilities is expected to give Israel a great security advantage. Therefore, the destruction of each segment of its military infrastructure offers a significant military advantage. Hence, even if a considerable number of civilians might be harmed during the attack of such a target, this would not necessarily be excessive incidental damage and therefore would not be a disproportionate attack that is illegal.”

In response, Professor Rubenstein writes, “The revision does not change the substance of the underlying position reflected in the original version and in the video cited.”

** This article has been updated with a reference to the Dec. 14, 2023 document published by the Israeli Ministry of Foreign Affairs.

Photo credit: Palestinians check the destruction in the aftermath of an Israeli strike the previous night in the Jabalia camp for Palestinian refugees in the Gaza Strip, on November 1, 2023, amid ongoing battles between Israel and the Palestinian Hamas movement. (Bashar Taleb/AFP via Getty Images)