What Makes a War Just?

Reports out of Gaza Tuesday that hundreds of Palestinians had been killed in a hospital blast—which now appear to be wildly inaccurate—underscored the debate coursing through the protests and proclamations surrounding Israel’s showdown with Hamas: Is this a just war?

And, assuming it is a just war, assuming Israel is right to strike back against Hamas, the terrorist group behind the October 7 attack on Israel—in which 1,400 were killed, women were tortured and raped, and 199 people, including many children, were kidnapped—can it be fought justly?

This is an especially tricky question when it comes to Gaza. Hamas stores weapons and other strategic assets in residential buildings, hospitals, mosques, and other places packed with civilians—which, in previous conflicts with Israel, has led to a disproportionate number of civilian deaths and made it easier for Hamas to win over public sentiment.

So on Wednesday, I turned to the prominent political theorist Michael Walzer, the author of Just and Unjust Wars: A Moral Argument with Historical Illustrations. 

The book was published in 1977, and it has had a profound impact on academics, policymakers, and elected officials in both major parties over the decades. John Yoo, the legal scholar who wrote the so-called torture memos defending waterboarding for President George W. Bush, said of Just and Unjust Wars: “The book’s influence is such that political leaders and opinion makers seem to seek out Walzer’s blessing every time the United States launches a war.”

I asked Walzer: Did tragedies like the explosion at (or perhaps near) the Al-Ahli Baptist Hospital, in Gaza City, raise doubts about the justness of this war? 

No, Walzer said—the war is justified—but it’s clear, he added, that Hamas “deliberately exposes” civilians to danger, and “the more civilians you kill, the more likely you are to lose the political war that always goes along with the military war.” 

Below is a transcript of my conversation with Walzer, who spoke with me from his apartment in New York City. It’s been lightly edited for the sake of clarity.

Peter Savodnik: Just and Unjust Wars argues that, for a war to be just, there must be a just cause, it must be declared by a lawful authority, all the other ways of resolving the conflict must have been exhausted, there must be a reasonable chance of success, there must be a net benefit, and there must be proportionality. Given all that, is Israel justified in waging war against Hamas?

Michael Walzer: That’s not actually my list. It’s the just war theory list. I have doubts about the value of proportionality. Anyway, I think the answer is yes. But that doesn’t mean that a just response should be a full-scale war tomorrow. 

PS: Hamas’s signature tactic seems to be to force Israel to kill civilians by placing military assets in places where there are a lot of civilians—like schools and hospitals. I’m wondering if it’s possible for Israel to fight a just war against Hamas?

MW: Well, it has to be possible. There always has to be a way of fighting a just war. And admittedly, yes, Hamas makes it difficult, because when you respond to an enemy that is fighting from civilian cover, you kill civilians who are perhaps the responsibility of Hamas, which exposes them quite deliberately. But the more civilians you kill, the more likely you are to lose the political war that always goes along with the military war. So it is a dilemma.

The way to respond politically as well as militarily is to use extreme caution about choosing tactics, choosing targets, and to require your own soldiers to take risks in order to minimize the risks they impose even on enemy civilians. This is a central argument both in the U.S. Army and in the IDF [Israel Defense Forces]: What risks can we ask our soldiers to take to reduce the risks they impose on enemy civilians who are being used by the enemy?

I’ll give you an example. I was at the Army War College a decade ago, and I met with a colonel back from Afghanistan who told me this story. American soldiers take fire from the roof of what looks like an apartment building. In the old days, before General [Stanley] McChrystal’s new rules of engagement, we would just pull back and call in an artillery strike. If there were people in the building, some of them would die, but we would get the bad guys on the roof. Now, he says, we can’t do that. So what are the alternatives? One is to send a scout undercover into the building to see if there are families in the building, and if there are, then we don’t call in the artillery strike, and if there aren’t, maybe we do. The other possibility is to get soldiers onto an adjacent roof so they can fire directly at the bad guys. Both of those new tactics put our soldiers at a risk that they wouldn’t face if we just called in the artillery. So that’s a good example of the kinds of risks that if we want to avoid bombing a building that may have families living in it, we need to ask our soldiers sometimes to take some degree of risks themselves.

PS: Let’s turn for a moment to the very tragic bombing, or what appears to be a bombing or blast, at this hospital in Gaza yesterday. 

MW: There’s now a lot of evidence that this is a misfired Islamic Jihad rocket. 

PS: In that case, how are we to assess the hospital blast? 

MW: Well, Hamas wanted to hit an Israeli hospital. They’re firing rockets not at military targets, they’re firing rockets at cities, in the general direction of Israeli cities and towns. They are certainly fighting an unjust war, and they are fighting it unjustly. 

PS: What about this question of net benefit? We need to know that, after this war is over, the world is going to be a better place. How can we be confident that whatever good that arises from an Israeli victory would exceed the destruction caused by it?

MW: We certainly can’t be confident in this situation, especially given that we really don’t know how Israel intends to fight the war. The current prime minister seems to try to play the role of an angel of vengeance, perhaps, to make up for his actual responsibilities for what happened. And if they fight a war of vengeance, it’s not likely to end well for anybody. But it’s at least imaginable that a war fought with a serious effort to minimize civilian casualties might end with some opportunities. I don’t know. The situation is so awful, but I still would hope for an Israeli response which is in accordance with the laws of war—a war fought that way would at least maintain the possibility of some progress afterwards, of some better aftermath. But this is a terrible time and I’ve never found it so difficult to think about what ought to be done. I’m so anxious about the likely full-scale invasion of 300,000 Israeli soldiers moving into terrain apparently with minimal intelligence about what’s going on on the other side and without knowing where the hostages are. It’s a situation where every decision is agonizing.

PS: Just and Unjust Wars, which you published in 1977, emerged out of this tension ten years earlier, in 1967. On one hand, you were arguing back then, at the height of the Vietnam War, against the war, but at the same time, for the morality of Israel’s preemptive strike against Egypt in the Six-Day War. You were trying to carve out this thoughtful space between the knee-jerk peace camp, the “anti–every war” people, as you put it, and, I guess you could say, the realists. Looking back, comparing then and now, do you feel less or more optimistic about Israel’s capacity to wage a just war?

MW: The government of Israel at the time of the Hamas strike was, I think, not only a terrible government politically and morally, but also an incompetent one. They have brought in a few competent people for the war council, but at this moment, as I am listening to the prime minister, I don’t have confidence that Israel will fight the right kind of war. I hope, but I can’t have confidence. And apparently, what is now going on on the West Bank is there are settler thugs attacking Palestinians, and the army is watching and not stopping it. It seems that the people responsible for the war, the war council, are not the people who are directly responsible for whatever is going on on the West Bank. I think [opposition leader Yair] Lapid was probably right to refuse to join a government which still included people like [Minister of National Security Itamar] Ben-Gvir, even if they were excluded from the war council. 

PS: As you know, within hours of news of Hamas’s attack on Israel surfacing, the anti-war activists and some government officials in the United States and Europe were already calling for an end to the violence—including any violence presumably the Israelis might take in the future on Hamas. That struck me as an immoral position. Because if Israel were to follow that advice, it would be inviting more attacks, more deaths of innocents. I wonder what you make of the anti-Israel demonstrators or camp who have insisted Israel has a moral responsibility not to respond.

MW: There have been two kinds of responses. On the farther left, there have been some appalling expressions of support for Hamas. And then, from other parts of the left or the pacifist world, there have been the calls that you just described for a cease-fire. The United States apparently vetoed a [United Nations] Security Council resolution that would have asked for a cease-fire, and I think that we were right to veto it. There has to be a response to an attack of the sort that Hamas carried out on October 7. There has to be a response. There also have to be arguments about how to respond, but there has to be a response. I think that has been the official position of the U.S. government.

PS: Are there certain weapons or tactics in particular that you think Israel has to rule out using? Are there certain things they should absolutely avoid doing? 

MW: The siege has come under a lot of criticism, and, interestingly, not only from the left. I read a very strong statement from the Begin-Sadat Center [a conservative think tank in Tel Aviv] against the cutoff of electric power for both political and moral reasons. I think the whole idea of the siege has hurt Israel far more than it has hurt anyone else on the other side except the civilian population of Gaza. There is a famous line from Maimonides about siege warfare. Do you know it?

PS: No, what is it?

MW: Maimonides says, with regard to sieges, “You can only surround a city on three sides.” That’s almost the quote. You can only surround a city on three sides in order to let people escape the city on the fourth side. It’s a wonderful sentence, because what it means is that you can’t surround the city.

If you’re going to ask people to leave, you have to help them wherever you send them. There has to be humanitarian aid to the southern part of Gaza, if you’re sending people to the southern part of Gaza. So that’s one military strategy or tactic that, I think, has to be avoided. As for weapons, I don’t know. I was opposed to the U.S. sending cluster bombs to Ukraine, but Israel doesn’t, I don’t think, use that kind of munition. 

PS: Does Egypt have any moral obligations to the people of Gaza, given that Egypt, like Israel, borders Gaza?

MW: The siege was a joint Israeli-Egyptian operation. The long-term blockade of Gaza wasn’t an Israeli blockade. It was a joint effort, and yes, at least with regard to humanitarian intervention, they certainly have an obligation to let supplies in. Do they have an obligation to take refugees? They don’t want Palestinians in the Sinai. Yeah, they have some obligation. I can’t say how many—100,000? Ten thousand? I don’t know. But they have an obligation, simply because they’re there.

PS: I want to go back to something you said a few minutes ago, about the appalling expressions of support for Hamas on the left. The levels of vitriol, the antisemitism on the far left, are unavoidable and disgusting and confusing. How do you make sense of that?

MW: There has always been left antisemitism. August Bebel, the German Social Democrat, called it the “socialism of fools.” And it has always been directed against the Rothschilds or Jewish bankers or Jewish control of the media. And it creeps in, sometimes, to the anti-Zionist stuff.

There have always been people on the left who believe that the struggle for national liberation, say, in Algeria, justifies terrorist attacks against French children. There’s the famous story of a bomb in a café where young people were gathered, and the left justifying that sort of thing on the grounds that you can’t tell the oppressed how to fight, you just have to support whatever they decide is necessary. 

That view has now focused very, very sharply on Israel. Israel has become the classic case for many leftists of the oppressed fighting against the oppressor, and they can do whatever they have to do, and we don’t judge them. It’s awful. It’s a very loud group on campus. But, from what I have heard, there are an awful lot of people that don’t like it. And there is a certain kind of Jewish response to that sort of thing which takes the form of saying, “All the world is against us.” And I think it’s very important to recognize the allies that we have. President Biden gave a stronger Zionist speech than I have ever heard from any Israeli politician. 

PS: Pivoting toward the future, are there telltale signs that will suggest Israel is heading in the right or wrong direction—that it is conducting a just or unjust war? 

MW: That’s very, very hard. You know, my friends in Israel now have grandchildren in the army, and what they say is everything depends on the lieutenant or the captain who is right there with the soldiers, who is the commander on the ground. Some of these commanders fight beautifully as well as effectively, and some of them are either incompetent or scared or frightened, really frightened, and they do bad things. And you don’t really find out about that until afterwards, until you sit and talk to some of the soldiers. Then you try to make judgments about what might have happened if this had been done rather than that, but at the moment, I think I will avoid it.

PS: Ultimately, if I understand you correctly, so much of this—determining whether a war is just or unjust—can only happen after the fact.

MW: You might know in advance that it is a just war. The question you’re asking now is: Will it be fought justly? I will withhold judgment, but we do know what ought not to be done, and we just hope it is not done. 

Peter Savodnik is senior editor at the Free Press. Read his latest column, on what “decolonization” really looks like, here.

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