Translating National Self-Defense to Military Operational Scale
By Prof. Geoffrey Corn
One of the most common criticisms of the Israeli military campaign against Hamas and Palestinian Islamic Jihad is that it is both overly aggressive and indiscriminate, resulting in a massive-scale of civilian casualties in violation of international law.
Setting aside the exaggerated narrative of indiscriminate killing (which I will address herein), this view reveals a fundamental misunderstanding of the intersection of international law and military strategy.
Indeed, it is international law that justifies the scale of the Israeli military campaign in Gaza, or more specifically the principle of necessity which forms the foundation of the inherent right of self-defense.
Very few experts question the premise that the Hamas attack that began on October 7th and continued thereafter triggered Israel’s right to use military force in self-defense. However, it is the scale of the military campaign that draws widespread ire; a scale that many critics assert cannot be justified by the law of self-defense.
But what is justified by self-defense is inherently threat dictated, and how that justification is translated into the objectives of a military campaign requires a military operational assessment of the nature of the threat and what is necessary to restore the safety and security of the State.
Right to self-defense: necessity and proportionality
Israel’s campaign against Hamas is, in international law terms, an exercise of this inherent right. The more complicated question is, for sure, what exactly does self-defense justify in terms of the scope, scale, and duration of military action?
It has become quite common for critics of the IDF campaign against Hamas and PIJ to assert it is too aggressive, producing too many casualties and too much physical destruction in Gaza. The ever-growing chorus of demands for an immediate and unconditional cease fire is the most obvious manifestation of this criticism, and condemnations like this add fuel to that fire. Those who embrace this view fail, however, to explain how it aligns with the inherent right of self-defense, or perhaps embrace some flawed conception of self-defense as some type of tit-for-tat equation requiring a proportionality of harm between the aggressor and the defender.
These understandings miss the point. Self-defense for a nation is analogous to self-defense for an individual: it legally justifies measures that would otherwise be unlawful when acting in response to an actual or imminent unlawful attack. But there is an important limitation on those measures: they must be reasonably necessary to reduce the threat and restore the status quo ante of safety and security. Indeed, self-defense is derived from the general legal justification of necessity, which means simply that if a measure is necessary it is justified; if it is not then it exceeds justification and remains illegal.
This is another way of saying that the response must be proportional to the threat, meaning that measures that exceed the necessity of reducing the threat to protect the nation are unjustified.
Israel is entitled to remove Hamas’ threat of annihilating Israel
This is why “tit-for-tat” self-defense arguments are so highly misleading: it is the threat that dictates the permissible scope of self-defense, not the suffering inflicted by the unlawful aggression that triggers the right. It is logical for a state to assess the scope of an imminent or ongoing threat by considering not only the opponent’s capability to inflict harm, but its motivation and intent.
To this end, it is important to remember that the express goal of Hamas is to annihilate Israel and kill as many Jews as possible, and that the only reason they didn’t succeed in killing more on October 7th and the following days is because Israeli security forces were able to repel the invasion and employ effective anti-missile counter-measures.
What scope of of military action is necessary?
Translated into military terms, this really leads to a very simple question: what scope of military action is necessary to secure the safety of the Israeli population from the Hamas (and Palestinian Islamic Jihad) threat emanating from Gaza?
That question cannot be answered by simply comparing casualty numbers. Even assuming some validity to the numbers provided by the Hamas controlled health ministry in Gaza (numbers which from inception have been dubious at best), the mere fact that more civilians have been killed in Gaza than were killed in Israel on October 7th or since does not indicate an excessive or disproportionate response. Instead, the more logical question is focused on whether it is reasonable to assess a necessity to dismantle Hamas as a fighting force capable of projecting violence against Israel, and what military action is necessary to achieve that objective?
In this regard, it is highly significant that in prior conflict flare ups, Israel attempted more limited military self-defense actions. October 7th proved that these limited responses failed to secure Israel from the Hamas threat and render reasonable the conclusion that nothing short of a full-scale campaign to achieve this dismantling of the enemy’s military capability was necessary.
Indeed, it is likely that historians will question whether Israel exercised unnecessary restraint up to this point, thereby exposing their population to constant rocket attacks, cross-border assault tunnel incursions and other attacks over the 16-year period in which Hamas has controlled Gaza.
The IDF’s military operational objectives
This is exactly how the strategic justification of self-defense was translated into IDF military operational objectives. The IDF was given a classic combined arms maneuver mission: close with and destroy the military capability of Hamas and PIJ. That mission was further translated to identifying, attacking, and defeating key aspects of this capability: command and control; logistics; weapons manufacturing capacity; military infrastructure; and action to render individual Hamas units combat ineffective. The IDF is close to achieving these key objectives. Then and only then will the government be able to offer its people a genuine sense of security along that dangerous border.
High casualty numbers do not prove illegality
Equally flawed is the view that the extent of (alleged) civilian casualties indicates an indiscriminate military campaign. Indeed, the mere fact that such condemnation is based on aggregate casualty numbers indicates the flaw in the analysis. This flaw is exacerbated by a focus on attack effects which, as also explained below, is inconsistent with the decision-based international humanitarian law derived test for assessing when an attack is indiscriminate.
But let’s take the bait and focus on aggregate attack effects. Doing so actually belies the assertion of massive-scale of indiscriminate killing. Indiscriminate in international legal terms means an attack decision that anticipates incidental civilian death and injury that is excessive in comparison to the anticipated concrete and direct military advantage. Even considering casualty figures in the aggregate (which as I will explain is inconsistent with the rules by which attack legality is assessed) and even accepting as legitimate Palestinian Health Authority casualty figures, the reality is that civilian deaths have been remarkably proportional to enemy deaths and certainly not excessive.
Even assuming every death reported by the Hamas controlled Health Ministry are civilians, and that every death was caused by IDF combat action (a dubious assumption at best). Now consider the IDF estimate that it has inflicted approximately 14,000 enemy casualties. This means there has been an approximate 1:2 enemy to civilian casualty ratio.
The casualty numbers in Gaza are proportionate
These attack outcomes justify the inference that the attack decisions were consistent with the international humanitarian law prohibition against launching indiscriminate attacks. To be clear, every single civilian killed in this conflict – Palestinian and Israeli – has been one too many for the simple reason that none would have suffered this fate but for Hamas’ barbaric attack. But it defies common sense to label IDF operations as “massively indiscriminate” when the consequence is such a close civilian to enemy casualty ratio, especially in such a complex combined arms combat operation as indiscriminate.
Indeed, there has probably never been an urban battle of this scale that resulted in anything close to this ratio.
It is the decision – not the outcome – that must be assessed
Even more problematic is the reliance on aggregate casualty numbers as the basis of this condemnation. Such aggregation says almost nothing about whether actual attacks conducted by the IDF qualified as indiscriminate within the meaning of international humanitarian law. This is because the law is not result focused, but instead conduct focused: what is regulated is the decision to launch an individual attack, not the outcome of that attack – either individually or collectively.
To condemn IDF attacks as indiscriminate requires insight into to the wide range of variable factors that led to the attack decision. While attack effects are relevant to this assessment, they are rarely conclusive. This is especially true in complex urban operational environments when confronting an enemy that pervasively exploits the presence of civilians to shield vital assets or even worse compel attacks that will cause civilian casualties.
Many lament that what is happening in Gaza undermines the credibility and efficacy of international law. But perhaps it is the exaggerated claims of IDF illegality, the failure to consider military operational context before condemning attacks as indiscriminate, and the gravitation towards “effects based” condemnations that is responsible for this impact?
Or, as David Brooks noted so eloquently in his recent New York Times editorial, if what the IDF is doing in Gaza is inherently illegitimate, please explain how defeating Hamas and eliminating this ongoing threat to Israel should have been better achieved?
Geoffrey S. Corn is George R. Killam, Jr. Chair of Criminal Law and Director of the Center for Military Law and Policy, Texas Tech University School of Law; Distinguished Fellow, JINSA Gemunder Center for Defense & Strategy; and Member, Center for Ethics and the Rule of Law Advisory Council.
