On October 7, 2023 thousands of Hamas terrorists forcibly entered sovereign Israeli territory where they killed, tortured, raped, or took hostage over 1,000 Israeli civilians and several hundred Israeli soldiers. The Israeli Defense Forces responded with a campaign of aerial strikes, followed by a ground incursion, eventually titled Operation Swords of Iron, targeting Hamas operatives and infrastructure deeply embedded in the Gazan civilian population. According to both Western estimates and Hamas casualty figures, the operation has killed tens of thousands of Gazans, a substantial majority of whom are believed to be civilians. The following is an explanation of relevant international legal principles as they relate to the October 7 terrorist attack and Israel’s response.
International Humanitarian Law (IHL) is the body of international law that governs the conduct of armed conflict. It is found in treaties such as the four Geneva Conventions of 1949 and in customary international law, i.e., general and consistent state practice observed due to a sense of legal obligation. Among other objectives, IHL seeks to limit unnecessary suffering during armed conflict, preserve the professionalism and humanity of combatants, and facilitate the restoration of peace.
Because Hamas is a non-state actor, the legal status of Gaza is contested, and Israel is a party only to certain IHL treaties, there is substantial debate about whether several IHL principles apply to the present Israel-Hamas conflict in Gaza. Nonetheless, there is widespread consensus that certain rules of IHL apply universally, regardless of whether a participant in a conflict is a state or a non-state actor, or whether the participant is a party to any particular treaty. Those rules include the requirements of Common Article 3 of the 1949 Geneva Conventions, which has been ratified by every state in the world, and other principles of customary IHL overwhelmingly acknowledged by states across the world.
Common Article 3 of the 1949 Geneva Conventions, which indisputably applies both to Israel and to Hamas, requires all parties engaged in the current conflict to treat humanely all people who take no active part in the hostilities. With respect to these non-combatants, the provisions of Common Article 3 expressly prohibit “violence to life and person,” “[o]utrages upon personal dignity, in particular humiliating and degrading treatment,” and “cruel treatment and torture.” Murder, rape, and the taking of hostages are all prohibited.
Customary IHL likewise prohibits using human shields and intentionally locating military operations in close proximity to civilian facilities. While states have the right to engage militarily in acts of self-defense, states must conform to the rules established by international law regarding armed conflict, including the principles of distinction and proportionality. The principle of distinction means that belligerents have an obligation to direct attacks only against combatants and military objectives and not to intentionally target civilians or civilian objects, such as schools, houses of worship, or medical facilities, so long as these objects are not used for military purposes. Similarly, belligerents are prohibited from using starvation of the civilian population as a method of warfare, or from deliberately targeting “objects indispensable to the survival of the civilian population” as such.
Consistent with the principle of distinction, civilian facilities can lose protected status under IHL if it is clear that they are being used for military purposes. For example, a hospital or school may become a legitimate military target if it contributes to a party’s military operations, such as serving as a weapons depot or housing fighters who do not require medical attention. To prevent this from happening, parties are not permitted to locate military facilities in close proximity to hospitals. If a hospital becomes a legitimate target, the opposing party must still attempt to protect any civilians present by conforming to the requirements of proportionality.
The principle of proportionality provides that combatants must refrain from a specific military attack if the expected loss of civilian life or injury to civilians, incidental to the attack, would be excessive in relation to the concrete military advantage expected to be gained. This analysis focuses on the combatant’s understanding based on the information reasonably available before the military operation has been effected; the proportionality of a strike thus turns on assessing both the extent of the anticipated civilian harm and the concrete military advantage the combatant expected to achieve before undertaking the specific military operation. There is no formula for determining whether the expected value of a military target justifies the expected harm to civilians. But the required analysis confirms that, under international law, collateral civilian harm is understood to be a tragic but often inevitable consequence of warfare. Whether such harm to civilians violates international law depends on conformity with the principle of proportionality.
The international legal principles of distinction and proportionality apply to all participants in warfare irrespective of whether one or both sides has violated them. Whether specific military operations accord with these principles is a fact-driven inquiry. A proper analysis of whether operations comply with IHL necessarily involves knowledge of the direct military objective that was expected to be achieved by a specific action and the extent of harm to civilian life and property that was anticipated based on the information available before the action was undertaken.
Applying these and other relevant international legal principles to the current conflict leads to the following findings:
Based on the foregoing analysis of fundamental norms of international law and related findings, we believe the following recommendations should be adopted by all parties to this conflict:
Both Israelis and Palestinians have already suffered tragically due to the horrific and unjustifiable attack of October 7th. However, one matter remains clear. The rigorous application of international humanitarian law is essential to prevent rewarding brutal aggressors and to help ensure a future peace.
This article represents the opinions of the authors and should not be construed to be official positions of either the American Bar Association or the International Law Section because they have not been adopted as policy of the Association.
