RUTHFULLY YOURS

The answer is no. One of the great tragedies of war is that civilians often become victims. That is why countries like Israel resort to war only as self-defense, which, according to the United Nations Charter, is every nation’s inherent right. But if even unintentional harm to civilians constitutes illegal “collective punishment,” as Rep. Alexandria Ocasio-Cortez has called Israel’s operations in Gaza, even defensive war is effectively precluded.

The law of war prohibits directly targeting civilians. Israel has made clear that its objectives are only military. “The IDF will destroy Hamas,” Defense Minister Yoav Gallant said Thursday, “and we will hunt down every last man with the blood of our children on his hands.”

But military targets can be attacked even when doing so may result in the loss of civilian life. International humanitarian law requires that civilian casualties from a particular action be balanced against “anticipated military advantage,” a rule known as proportionality. In practice, as this rule is understood by Western countries, even significant civilian casualties don’t necessarily make strikes on legitimate targets illegal.

Hamas has violated international law by hiding among civilians. But international law doesn’t reward the use of human shields. Instead, it makes clear that “the presence of civilians within or near military objectives does not render such objectives immune from attack.” Israel’s critics want it to fight in a way that would have made it impossible for democracies to wage war in every conflict from World War II to the U.S.-led campaign against ISIS, which killed about 10,000 civilians by some estimates.

A legal analysis of Israel’s response must take into account the barbarity and scale of Hamas’s attack. Israel now knows that Hamas’s goal is the annihilation of the Jewish people and the Jewish state. Defeating Hamas isn’t simply a tactical military goal but an existential national one—a military objective of the highest order. There is no basis on which to bar Israel ex ante from a generally lawful means of warfare such as siege, or maneuver in urban areas.

Israel’s critics will denounce any significant measure the country deploys as a war crime. Israel has laid siege to Gaza, prompting the usual array of EU-funded organizations to accuse it of starving civilians and violating the law of war. But siege is a “legitimate” and ordinary part of lawful war, in the words of the U.S. Defense Department law-of-war manual. As West Point law professor Sean Watts put it in 2022, “Siege—or encirclement as military doctrine refers to it—is an essential aspect of modern military operations. . . . Only starvation directed specifically at civilians is prohibited.”

This should be obvious: An army need not help its enemy obtain provisions during a conflict. When military objectives and civilians are intermingled, siege aimed at the former also will affect the latter. As with other situations of collateral damage to civilians, international law permits a siege as long as it isn’t “for the purpose of denying sustenance to the civilian population.”

There is no indication that Israel has any strategy of starving out civilians. Nor could it. Gaza has a long border with Egypt, which has long been used by Hamas to smuggle supplies. The evacuation of civilians is a standard measure to avoid humanitarian crises. Israel has moved tens of thousands of its own citizens away from the area along the Gaza border. Hamas, by contrast, has ordered its civilians to stay put, presumably to increase the tally of civilian deaths for propaganda purposes.

Egypt is cruelly denying entry to those fleeing the war zone. Israel’s critics clearly aren’t interested in saving civilian lives, because they aren’t offering to take in Gaza’s civilians. Nobody says refugees from Iraq, Syria and Afghanistan should be trapped in conflict zones. European countries consider it a virtue to accept them as refugees. But to Hamas’s human shields, the world says: “Don’t go anywhere, we want you right where you are.”

It is unclear whether such voices are merely naive or wish to leave Israel perpetually exposed to genocide. What is clear is that if these voices prevail, the commitment of modern international law will have changed from “Never again” to “Whenever they want.”

Mr. Kontorovich is the head of the international law department at the Kohelet Policy Forum, a Jerusalem think tank, and a professor at George Mason University Scalia Law School.