While it stopped short of explicitly demanding a ceasefire, the top court of the United Nations on Friday acknowledged there is a plausible risk of genocide in the bombarded Palestinian enclave and refused to dismiss the case brought by South Africa.

“It’s a huge defeat for Israel — one of the biggest defeats … in the past 75 years,” said Raed Jarrar, advocacy director at Democracy for the Arab World Now (DAWN), a think tank in Washington, DC.

But the ruling “goes beyond Israel” alone, Jarrar told Al Jazeera, as it highlights countries’ legal and political obligations to take action to prevent the alleged genocide unfolding in Gaza.

The ICJ’s decision in The Hague also spurred renewed calls to suspend weapons transfers to the Israeli government, which advocates say amount to complicity and violate international law. That includes arms shipments from the United States, Israel’s foremost backer.

“It’s a watershed moment where the United States government is put on notice that they cannot continue their blank-cheque policies with Israel,” Jarrar said.

“The US can’t and should not continue its arms transfers with Israel now.”

Not a ‘goodwill gesture’

The US provides at least $3.8bn in military aid to Israel annually. For years, rights advocates and a growing number of US lawmakers have called on Washington to condition that assistance on Israel’s human rights record and international law.

However, US President Joe Biden has rejected those efforts while bolstering assistance to the Israeli government.

After Israel began the Gaza war on October 7, following an attack by Hamas that killed more than 1,100 people in southern Israel, the Biden administration sent a request to Congress to approve a $14bn foreign aid package for Israel, the bulk of which would be military assistance.

The US government also twice bypassed Congress to provide thousands of artillery shells to the country as it continued to bombard Gaza. Israeli attacks have killed more than 26,000 Palestinians to date and decimated the coastal territory.

Yet, despite reports and investigations that showed US weapons were used in Israeli bombings that killed Palestinian civilians in Gaza, attempts to pressure Washington to end the transfers or determine whether the arms are being deployed in rights abuses have failed.

“We have been telling the Biden administration that this is not just a goodwill gesture” to end the transfer of weapons to Israel, said DAWN’s Jarrar, explaining that Washington has obligations under international and US law.

“This is something that they have to think about very seriously because the United States as a government is implicated in these war crimes, and US officials are also implicated,” Jarrar said. “They have to take today’s order [from the ICJ] very seriously.”

International treaties

Rights groups have called on all UN member-states to suspend their transfers of weapons that “can be used to commit violations of international humanitarian and human rights law” in Gaza.

Among other countries, Canada and the United Kingdom faced growing pressure on Friday following the ICJ’s decision. Both nations are state parties to the Arms Trade Treaty, a UN pact that seeks to regulate the flow of weapons globally and prevent them from being used in violations of international law and human rights.

It prohibits parties from greenlighting arms transfers “if [they have] knowledge at the time of authorization that the arms or items would be used in the commission of genocide, crimes against humanity, grave breaches of the Geneva Conventions of 1949, attacks directed against civilian objects or civilians protected as such, or other war crimes”.

The UK has licensed more than 474 million pounds ($602m) worth of military exports to Israel since 2015, according to Human Rights Watch (HRW), and it “provides approximately 15% of the components in the F-35 stealth bomber aircraft currently being used in Gaza”.

Pressed on UK arms exports to Israel in November, Defence Secretary Grant Shapps said the country’s “defence exports to Israel are relatively small — just 42 million pounds [$53m] last year”. The weapons also “go through a very strict criteria before anything is exported”, Shapps said, according to a parliamentary transcript.

But on Friday, Yasmine Ahmed, the UK director at HRW, said the ICJ’s provisional order should push the UK government to “halt arms exports to Israel with immediate effect”. “There is NO question,” she wrote on social media.

“The Court found a plausible risk of genocide & the UK has an obligation to prevent genocide & not be complicit.”

There is NO question. In light of the provisional measures judgment @CIJ_ICJ, the 🇬🇧 must halt arms exports to Israel with immediate effect @David_Cameron @KemiBadenoch

The Court found a plausible risk of genocide & the UK has an obligation to prevent genocide & not be complicit

— Yasmine Ahmed (@YasmineAhmed001) January 26, 2024

That obligation stems from the UN’s 1948 Convention on the Prevention and Punishment of the Crime of Genocide — commonly known as the Genocide Convention. The US, the UK and Canada are among 153 countries that are parties to the treaty.

It confirms “that genocide, whether committed in time of peace or in time of war, is a crime under international law which they undertake to prevent and to punish”.

South Africa invoked this “obligation to prevent genocide” when it brought its case to the ICJ, and the court on Friday recognised that it had standing under the Genocide Convention. The treaty also states that “complicity in genocide” is punishable.

“If you’re supplying arms to a country where you know the arms may be used for criminal purposes, then you may become complicit in those crimes,” said Geoffrey Nice, a UK lawyer who led the prosecution of Slobodan Milosevic at the International Criminal Tribunal for the former Yugoslavia.

“And it’s very hard not to become complicit after a certain stage of knowing is reached and after a certain stage of conduct continues,” Nice told Al Jazeera in a television interview on Friday.

“Arms suppliers would have to be very, very careful – and some may simply decide it’s not worth the risk of being brought into a humiliating, serious, possible investigation for crime.”

‘No other option’ but to suspend arms exports

Most countries also have their own regulations around weapons exports.

For example, Canada’s Export and Import Permits Act obliges the minister of foreign affairs to “deny exports and brokering permit applications for military goods and technology … if there is a substantial risk that the items would undermine peace and security”.

The minister should also deny exports if they “could be used to commit or facilitate serious violations of international humanitarian and human rights laws” or in “serious acts of gender-based violence or serious acts of violence against women and children”.

Last year, Canada exported 21.3 million Canadian dollars ($15.7m) worth of weapons to Israel.

Canadian antiwar group Project Ploughshares said in a recent report that Canada-made components transferred to the US also eventually end up being supplied to the Israeli military, including components used in F-35 aircraft.

“Because the vast majority of Canadian military exports to the United States are neither regulated nor reported, exact volumes and values of these exports are not available to the public and remain unknown,” the report said.

Michael Bueckert, vice president of the advocacy group Canadians for Justice and Peace in the Middle East, said Canada has been sending weapons to Israel “for many years despite significant human rights violations and war crimes”.

But the gravity of those transfers has increased significantly after the ICJ’s decision, he said.

“There’s just no other option from the perspective of preventing Canada’s complicity in potential genocide; Canada must cancel all exports and suspend the arms trade completely to make sure that it’s not aiding or abetting those grave crimes,” Bueckert told Al Jazeera.

“There’s no such thing as safe exports of military goods from a human rights perspective in the context of possible genocide. Canada has to go above and beyond to make sure that it’s not contributing in any way.”

Global Affairs Canada did not immediately respond to Al Jazeera’s request for comment on the calls to end arms transfers to Israel.