Violence in Gaza has increased in recent months, and casualties are high. To what extent does International humanitarian law protect civilians?

'One of the main goals of international humanitarian law, abbreviated as IHL, is to protect civilians and others who do not participate in hostilities. In that sense, the law protects the civilian population. But if you read the news reports about the war in Gaza, you might wonder if that is the case in practice. The devastation is enormous; there are many human casualties, and according to the UN there is now almost a famine. Yet, when there are civilian casualties, it is not automatically the case that there has been a violation of IHL. IHL represents a balance between the realities of war and military considerations on the one hand and the need to protect the civilian population as much as possible from the effects of military action on the other. That balance is reflected in virtually all specific rules. An IHL that would not protect civilians would not be "humanitarian". However, an IHL that would make warfare impossible would not be acceptable to states and ignores the balance mentioned before. Law assumes that civilian casualties are inevitable in some situations. Certainly in a densely populated war zone like Gaza.'

Is International humanitarian law really honored in war situations?

'We see that the parties in this conflict do not always comply with IHL, with dire consequences for the civilian population. Hamas seems to disregard the law, for example, by deliberately attacking and taking Israeli civilians hostage and by using civilians as human shields. Among other things, Israel does not seem to be doing enough to ensure that adequate humanitarian aid enters Gaza, which it is obliged to do under the Geneva Conventions.'

Much is written about the principle of proportionality concerning the war in Gaza. What exactly does this mean?

'The principle of proportionality is one of the basic principles of IHL. It is also a good example of the balance between military and humanitarian considerations I mentioned. Under this principle, an attack on a legitimate military target is prohibited if the expected "collateral" damage to civilians is excessive compared to the anticipated military advantage of that attack. The greater that advantage, the more "collateral damage" is permissible under IHL. Both involve what the commander knew or should have known in advance. That often makes it difficult for outsiders like me and fellow academics to judge whether the principle has been respected because that information is usually unavailable. That is why it is important to have independent investigations of alleged violations, for example, by the UN and the International Criminal Court.'

Meanwhile, the word genocide is mentioned frequently. Is there sufficient evidence to establish that Israel is committing genocide?

'There is a case pending before the International Court of Justice (ICJ) brought by South Africa against Israel. According to South Africa, Israel is violating the Genocide Convention by committing genocide itself and by failing to prevent genocide. Among other things, the country points to the limited aid entering Gaza. Because the Court's jurisdiction in this case is limited to assessing the situation under the Genocide Convention, other possible violations of international law, such as war crimes, are outside the jurisdiction of the ICJ. What makes it difficult to prove the commission of genocide is that to do so, it must be shown that certain acts were committed with a so-called "special intent." They must have been committed with the intent of destroying a specific ethnic, religious, racial or national group. Violations of the law of war, even widespread and systematic ones, are not necessarily genocidal. As I said earlier, I am deeply concerned that Israel is not fulfilling its obligation to allow adequate humanitarian aid through to Gaza, but that does not necessarily mean that this is an act of genocide.'

Lawyers are known to be precise when it comes to language. How can they still have such different opinions on this?

'The conflict in Gaza evokes many emotions. You can see that in the demonstrations at our university as well. The conflict also affects lawyers. I don't rule out that some lawyers' legal analyses are colored by their political preferences. But that, I think, is not, in most cases, why lawyers differ. A bigger factor is that the rules of IHL are worded so that they are open to multiple interpretations. As a result, they are also interpreted differently by states, lawyers, and judges. In addition, some rules contain elements that are, to some extent, subjective. The principle of proportionality is another example of this. Some will find a certain ratio between harm to civilians and military advantage excessive; others will not. And finally, lawyers, though not known for it, are sometimes sloppy in their use of language. For example, a few weeks ago the office of the UN High Commissioner for Human Rights came out with a report stating that Israel most likely committed indiscriminate and disproportionate attacks. However, the report misrepresents proportionality. It suggests that that principle would prohibit not only disproportionate but also extensive harm to civilians. However, that is not a generally accepted interpretation of this principle.'

Why is it important to use terminology correctly when discussing this conflict?

'My colleague Göran Sluiter (Professor of International Criminal Law at the University of Amsterdam, ed.) rightly stated in a recent interviewExternal link by the Amsterdam Law School that the correct use of terminology is important because terminology affects policy choices. I would add that law gives us a language that, to some extent, allows us to talk about conflict without involving politics or religion. For this, however, it is a prerequisite that we be very precise in terminology. Lawyers must also be careful about imputing principles to others or disqualifying interpretations that differ from their own.'

What else strikes you in the coverage of the war in the Middle East?

'There are several things that strike me. One is that there seems to be increasing doubt about the usefulness of the law of war in limiting human suffering in conflict. There seems to be a perception that the law can be violated without consequences. A second thing that strikes me is that there is a great need for interpretation of events by experts. From a military perspective, this is done by colleagues of mine at the Netherlands Defense Academy, among others. That, as a result, the protection of the civilian population would receive insufficient attention, as Göran Sluiter seemed to suggest, I do not agree with, nor do my colleagues Terry Gill (emeritus professor of Military Law at the UvA, ed.) and Paul Ducheine (extraordinary professor of Military Cyber Operations at the UvA, ed.).'

What drives you to get involved in the public debate?

'I see a great need from the media and society for legal interpretation of the conflict. As an academic, I feel it is my responsibility to contribute. In doing so, I try to dispel the impression that IHL has no added value.'