Hamas is bound by international law. But compliance is a different matter.

By Amanda Taub

Oct. 7, every legal expert I have asked has shared one conclusion: Hamas’s attacks on civilians that day, including killing, torture, and hostage-taking, were war crimes. And because many hostages are still being held, that crime remains ongoing.

Tom Dannenbaum, a Tufts University professor, told me just days after the attack that there was “no question” Hamas’s attack had involved multiple war crimes. “Those are not close calls,” he said.

Since then, evidence has continued to mount. Last month, the prosecutor of the International Criminal Court announced that he was seeking warrants for the arrest of three Hamas leaders on charges of war crimes and crimes against humanity relating to the Oct. 7 attack on Israel, as well as the hostage-taking that followed. He also sought warrants for two Israeli officials. All of the subjects of the warrant requests have denied the accusations against them.

Last week, a U.N. commission concluded that there was credible evidence that members of Hamas and other armed Palestinian groups committed war crimes on Oct. 7, including by killing civilians, carrying out torture, and taking hostages. The commission also found evidence of Israeli war crimes, including the use of starvation of civilians as a weapon of war.

There are a lot of misperceptions about Hamas’s obligations under international law, so I thought I would use today’s column to explain those rules, how they apply to Hamas, and the surprising incentives they might create. Hamas declined to comment for this article but in past statements the group has claimed its fighters have a “religious and moral commitment” to avoid harm to civilians.

A quick note: I’m not going to write about Israel’s alleged war crimes in this post. I have written about a number of those issues previously however, including the use of starvation as a weapon of war, and the legal questions raised by the Israeli military’s attack on the World Central Kitchen aid convoy.

Hamas isn’t a state. Does it still have to follow international law?Hamas is an armed Islamist group that was founded in 1987, and has been designated as a terrorist organization by the United States and the European Union. It won legislative elections in Gaza in 2006 and has held power there since 2007 without holding further elections. But it’s not a state government: Even countries that have recognized Palestinian statehood do not recognize Hamas as its government.

There are two main things you need to know to understand Hamas’s obligations under international law. The first is that even though it is not a state government, it is still bound by the laws of war.

“The applicability of the law is triggered by the existence of an armed conflict,” said Janina Dill, co-director of the Oxford Institute for Ethics, Law, and Armed Conflict. Once conflict begins, every organized armed group participating is bound by international humanitarian law.

The second point is that those laws are universal, not reciprocal. Violations by one party to a conflict do not change the obligations of the other. Conversely, no military cause is so just that it allows its proponents to violate international humanitarian law in order to achieve it.

“The law of armed conflict has a very clear position,” said Marko Milanovic, a professor of public international law at the University of Reading in England, “which is that all parties have the same obligations regardless of how just their overall cause is, and regardless of whatever legitimacy or alleged illegitimacy of that entity.”

In addition, all individuals are subject to international criminal law regardless of whether they are affiliated with a government or nonstate armed group.

That equal application can seem outrageous to people who believe one side of a conflict has a just cause. After the I.C.C. prosecutor announced he was seeking warrants for leaders of Hamas and Israel, both Israel and Hamas issued irate statements about being placed in the same category as their opponents in the war.

But the core purpose of those laws is to shield civilians, who are entitled to the same protections regardless of whether a state military or a nonstate armed group threatens them. So there is no number of Palestinians detained by Israel that would make it legal for Hamas to take Israelis hostage, just as there is no number of Israelis killed on Oct. 7 that would make it legal for Israel to kill Palestinian civilians indiscriminately or disproportionately.

If there are no cops to enforce international law, does it still matter?When I write about these issues, I often receive messages from people who want to know why they should take international law seriously, given that there is no international equivalent of the FBI to arrest miscreants or enforce court judgments.

I can understand that sentiment: Given the broad consensus that Hamas committed war crimes, the inability of the international legal system to address those acts immediately can make it seem like an ineffective or even futile institution, particularly when compared to domestic legal systems. When a murder is committed in a country with a functioning judicial system, we hope the perpetrator will be brought to justice — though of course that often doesn’t happen — and we know who has the power to do so. The lack of enforcement authority in the international system can be jarring.

But international law relies more on diplomacy and negotiation than top-down enforcement. If states do not voluntarily carry out arrest warrants or abide by the judgments of international courts, there is no central authority to force them to comply.

That doesn’t mean international law is pointless. On a basic level, the rules that govern conflict can act as a deterrent, creating standards for legitimacy that can become a source of external and internal pressures on armed groups.

Dill, who researches compliance with international law, has found that when militaries receive legal training, they often internalize those norms as a measure of their own professionalism. She said U.S. service members, for instance, often told her that they saw themselves as “professionals” who fought according to the law, which they believed distinguished them from their opponents, whom they described as terrorists and murderers.

And Tanisha Fazal, a political scientist at the University of Minnesota, has found that armed groups trying to establish new independent states often complied with international humanitarian law as a way to “signal their capacity and willingness to be good citizens of the international community to which they seek admission.”

When it comes to Hamas and the current conflict, it’s fair to say those incentives do not seem to be working.

Palestinian statehood is one of Hamas’s goals. But the Palestinian Authority, not Hamas, is treated as Palestinians’ representative on the international stage, making that a crowded field in which to compete. Hamas, as a designated terrorist organization, may see little prospect of international acceptance.

Nor does the group appear to believe that support from ordinary Palestinians depends on demonstrating compliance with international law. Its fighters filmed themselves carrying out the Oct. 7 attacks and Hamas posted some of the material publicly, which suggests it may have anticipated gaining legitimacy as a result of the violence.

But while many Palestinians took to the streets as the attacks were unfolding on Oct. 7 to celebrate what they saw as a humiliation for an occupier, the boost to Hamas’s popularity seems to have proved temporary. Today, many in Gaza hold the group responsible for starting a war that has brought catastrophic harm to civilians.

Will Hamas ever be held to account?A recent article in The Wall Street Journal suggested that Yahya Sinwar, the leader of Hamas, made what it called a “brutal calculation” that civilian deaths in Gaza would help the group by increasing pressure on Israel. The article cited correspondence from Sinwar, including a message in which he reportedly described civilian losses as “necessary sacrifices.”

The New York Times has not seen these messages or been able to independently confirm them. But if Hamas was deliberately putting civilians in harm’s way by, for instance, hiding fighters inside crowded refugee camps, schools or hospitals — as some evidence suggests — it would be in breach of international law, which forbids the use of human shields, or the placement of military installations in densely populated civilian areas.

That said, even if one side uses human shields, this does not exempt the other side from its obligations: Civilians remain entitled to protection even if one party to the conflict has already endangered them by violating the law.

For now, the gap between the apparent evidence of war crimes committed by Hamas and the accountability of its leaders in a court of law can feel impossibly wide. But it may not always be so.

The I.C.C. has a track record of prosecuting members of nonstate armed groups and its arrest warrants do not expire. Even if the war ends, the potential criminal liability of Hamas’s leaders will not.