Israel has described its indiscriminate bombing of Gaza, and its targeting of hospitals, schools, shelters, refugee camps and civilian cars, as lawful self-defense. While states, like individuals, have that right, international law has long put important restrictions on the exercise of that right. Self-defense is an exception to the prohibition against use of force under the UN charter and customary international law, and as an exception should be interpreted narrowly. Some of Israel’s supporters, while disagreeing with its excesses, have asserted that it has the right to defend itself, which has been misconstrued as implicitly condoning its relentless attacks against Gaza. There have been clarifications, but not enough to dispel the notion that some Western nations are acquiescing. Clearly, war to avenge an earlier attack, no matter how gruesome, cannot be legally considered in itself as legitimate self-defense, and even when it is so considered, it needs to be carried out in accordance with those rules of war, including the rules of necessity, proportionality and sanctity of civilians and civilian structures. According to the Geneva Conventions as interpreted by the International Committee of the Red Cross and the International Court of Justice, the rule of necessity requires that force may be lawfully used in self-defense only when this is necessary to bring an attack to an end, or to avert an imminent attack, and there must be no practical alternative to the proposed use of force that is likely to be effective in ending or averting the attack. In other words, force should not be the first recourse but the last, when all peaceful means have been exhausted, and when there is no practical non-military alternative. Force must be limited to what is necessary to avert an imminent attack or bring it to an end. Self-defense must also comply with the rule of proportionality, which has been misapplied in the Gaza conflict. It means that the force used must not be excessive in relation to the need to avert or bring the attack to an end. The human, physical and economic consequences of the force used must not be excessive in relation to the harm expected from that attack. The proportionality criterion also means that the physical and economic consequences of the force used must not be excessive in relation to the harm expected from the adversary’s attack.The right of self-defense does not permit the use of force to “punish” an aggressor and, as such, proportionality should not be thought to refer to parity between a response and the harm already suffered from an attack, as this could turn the concept of self-defense into a justification for retributive force. Protection of civilians during war should not be controversial. In modern times, that hallowed principle was codified in the Geneva Convention of 1864 and the Hague Convention of 1907. After the Second World War, the rules were rewritten to enhance that protection of civilians, in light of the unspeakable atrocities against them during the war, especially against Jewish communities in European lands overrun by Nazi Germany. The four Geneva Conventions of 1949 and their additional protocols of 1977 have been signed and ratified by 196 countries — all of the UN 193 member states, plus the two non-member UN observer states (the Holy See and Palestine), and the Cook Islands. There are few international instruments that have been so unanimously accepted. The Fourth Geneva Convention is dedicated to protecting civilian populations. While Israel has ratified that convention, it has unilaterally declared that it does not apply to its occupation of Palestinian lands including Gaza. It claims that it alone decides how to treat Palestinians in Gaza and the West Bank. The UN has repeatedly reaffirmed the applicability of the Geneva Conventions to the Occupied Territories, as has the US, Israel’s closest ally, and almost every other nation and legal authority addressing this issue. Failure to uphold international humanitarian law in the war against Gaza has been the main bone of contention between Israel and the international community and certainly its neighbors. As Israel refuses to observe international humanitarian law in Gaza, it is not clear what legal yardsticks it uses to guide its military’s conduct. Many were alarmed when, on Oct. 10, Defense Minister Yoav Gallant told his soldiers: “We have removed every restriction.” Then, on Oct. 29, Prime Minister Benjamin Netanyahu compared the attacks on Israel to those of the Amalekites in ancient history. Citing the Old Testament, he said: “Remember what Amalek did to you. We remember and we fight,” according to the translation published by his office. Invoking this bloody episode was ominous, because the rest of the text he cited goes on to say: “You must destroy the Amalekites and erase their memory from under heaven. Never forget this.” In another chapter, it said that the memory of the Amalekites was indeed “erased” after they were put to the sword in later attacks. The no-holds-barred policy described by Israel’s defense minister and the genocidal vengeance cited by the prime minister should not be acceptable substitutes for the Geneva Conventions.