South Africa’s genocide case against Israel at the International Court of Justice (ICJ) is usually presented as a dispute about the conduct of the Gaza war. But increasingly, something much larger is at stake: what the word “genocide” itself means.

Since the Genocide Convention was adopted in 1948, genocide has required something more than large-scale civilian deaths, disproportionate military action, or even war crimes. It requires dolus specialis – the specific intent to destroy, in whole or in part, a national, ethnic, racial, or religious group as such. This is a deliberately high threshold. The ICJ has held that where genocidal intent is inferred from a pattern of conduct, that intent must be the “only inference that could reasonably be drawn” from the acts in question.

This requirement has consequently become one of the central battlegrounds in contemporary genocide law.

The debate did not begin with South Africa’s case against Israel. An important precursor was The Gambia v Myanmar, brought in 2019 over Myanmar’s treatment of the Rohingya.

In November 2023, Canada, Denmark, France, Germany, the Netherlands, and the United Kingdom – then governed by Rishi Sunak’s Conservatives – jointly intervened in the Myanmar case. They argued that the existing “only reasonable inference” test should be interpreted in a “holistic” way. 

Ireland subsequently entered the debate. It intervened in The Gambia v Myanmar in December 2024 and filed a declaration of intervention in South Africa v Israel in January 2025.

Ireland’s argument goes considerably further. It argued that when assessing intent, the court may consider whether destruction of the protected group was the foreseeable consequence of a state’s conduct.

Evidentiary Threshold

In practice, these approaches, critics contend, significantly lowers the evidentiary threshold required to prove specific genocidal intent (dolus specialis). Foreseeing that an action may cause destruction is not necessarily the same thing as intending that destruction. The authors of a recent law blog Opinio Juris analysis argue that moving towards foreseeability would risk transforming genocide from a crime of specific intent towards something resembling a negligence standard.

If the ICJ changes the way genocidal intent can be inferred, the practical meaning of genocide could therefore change. South Africa’s case against Israel would then be litigated against the background of a legal development that began in a very different dispute.

This adds another South African dimension to the participation of jurist Navi Pillay.

Pillay has had one of the most distinguished careers in international human-rights law. She served for eight years on the International Criminal Tribunal for Rwanda, including four years as its president, before becoming a judge of the International Criminal Court. In 2008, she became United Nations (UN) High Commissioner for Human Rights.

At the same time, Pillay has faced sustained criticism over her previous public positions on Israel. She has publicly compared Israel’s treatment of Palestinians with apartheid and expressed support for boycotts, divestment, and sanctions of the country. In 2020, she advocated measures including an arms embargo, suspension of free-trade agreements, and targeted sanctions against Israel. In 2021, she again drew comparisons with apartheid South Africa and signed a letter to United States (US) President Joe Biden condemning Israel’s “domination and oppression of the Palestinian people”.

In 2021, Pillay was appointed chair of the UN Independent International Commission of Inquiry on the Occupied Palestinian Territory, including East Jerusalem, and Israel. The Commission attracted criticism because its mandate was permanent rather than limited to a specific period or incident. Critics of the Commission have argued that this creates an institutional bias that does not exist anywhere in the system and questioned her impartiality on Israel-related inquiries.

Pillay announced her departure from the Commission in 2025. Officially she cited her age, medical issues, and the weight of other commitments. However it has been claimed that she resigned because of threatened US sanctions.

More importantly for the genocide debate, The Gambia selected Pillay as its judge ad hoc in its case against Myanmar. She was installed in that role in December 2019 and participated in the court’s 2022 jurisdictional judgement. She continues to sit as The Gambia’s judge ad hoc in the case. As such she will have a role in judging questions of genocide that legal scholars have argued that could shape jurisprudence “for a generation”. It will also have direct consequences for South Africa’s case against Israel.

Myanmar Case

The Myanmar case concerns military operations against the Rohingya, a largely civilian minority population. The Gaza conflict, by contrast, involves intense urban warfare between Israel and Hamas, an organised armed group. This distinction matters because the ICJ’s existing test requires genocidal intent to be the only reasonable inference from a pattern of conduct. Where military operations are directed against an organised armed adversary operating within a civilian environment, alternative explanations for civilian deaths and destruction may have to be considered when determining intent.

If genocide can increasingly be established through foreseeable consequences (as argued by the Ireland) rather than a demonstrated intention to destroy a protected group, the same reasoning will not remain confined to Israel. Western militaries frequently operate in environments in which civilian deaths, displacement, and destruction are foreseeable consequences of military operations against armed organisations embedded within civilian populations.

The issue is consequently much bigger than whether one supports Israel or South Africa’s case against it. The Genocide Convention was created to identify an exceptionally specific crime: the intentional destruction, in whole or in part, of a protected group. Changing how that intention is proved could ultimately change the practical meaning of genocide.

And once the threshold moves, the resulting jurisprudence will not apply only to Israel. American operations against the Islamic State, British operations in Iraq and Afghanistan, French interventions in Africa, North Atlantic Treaty Organisation (NATO) campaigns, as well as multinational or UN-authorised military operations could face arguments constructed from the same legal principles.

This would open the door for authoritarian governments to invoke an expanded understanding of genocide against democratic states responding to armed groups or atrocities abroad, turning a legal doctrine developed for the prevention and punishment of genocide into a tool of strategic litigation.