Montreal, Canada – The United States has faced widespread condemnation this week for authorising the sale of more than $20bn in additional weapons to Israel as the top US ally wages war in the Gaza Strip.

But while the newly approved arms transfer has renewed global scrutiny of Washington’s unwavering support for Israel, in Canada, the announcement on Tuesday drew attention for a different reason.

That’s because more than $60m worth of munitions will be manufactured by a weapons company in Canada as part of that sale.

Canadian lawyers, rights advocates and other experts say this raises serious questions about the opaque nature of the country’s arms export regime.

They also say Canada’s participation in the arms deal makes clear that the country is failing to ensure that Canadian-made weapons are not used in suspected human rights violations abroad, as required by law.

“The news is appalling,” said Kelsey Gallagher, a researcher at the Canadian peace research group Project Ploughshares.

“Given Israel’s appalling track record of violating international humanitarian law through its operation in Gaza, including in some cases which may constitute war crimes, in no way is it appropriate for Canada to supply this ammunition,” Gallagher told Al Jazeera.

“Moreover, as per Canada’s obligations under the UN Arms Trade Treaty, it’s illegal.”

US-Canada defence partnership

How is it that Canadian-made munitions will be making their way to Israel? A special US-Canada trade relationship is at the heart of the issue, experts say.

Since the 1950s, the North American neighbours have enjoyed “mutually beneficial terms and conditions” on the trade of military weapons and related components via a bilateral deal called the Defence Production Sharing Agreement.

The US — Canada’s largest overall trading partner — today represents the largest market for Canadian-made defence goods, accounting for about 49.1 percent of all such exports.

When Canada joined the Arms Trade Treaty (ATT) in 2019, it sought to ensure that its accession to the United Nations pact wouldn’t affect its longstanding arms export regime with the US.

The ATT regulates and sets conditions for the global flow of arms, including a prohibition on signatories transferring weapons to another country if there is a plausible risk they could be used in violations of international humanitarian law, such as war crimes.

“Canada has benefited greatly from its privileged defence relationship with the United States, and it is important not to undermine this arrangement,” the Canadian government said in a statement when it joined the international treaty.

After joining the ATT, Canada put some limited reporting requirements in place when certain weapons systems are sold to the US. Still, it does not report on most transfers to its southern neighbour, nor does it require specific permits for them.

In effect, “Canada and the United States have reciprocal arrangements to ensure permit-free/licence-free movement of most military items between our two countries”, the Canadian government says on its website.

‘Flawed’ export controls

Canadian human rights advocates have denounced this lack of transparency for years, dubbing it a dangerous “loophole” to the Canadian arms export system.

The obscure nature of Canadian arms transfers to the US is also why this week’s news — that a company based in the province of Quebec would be the main contractor for the $61.1m in munitions to Israel — came as a surprise to many observers in Canada.

In its announcement, the US’s Defense Security Cooperation Agency (DSCA) said that General Dynamics Ordnance and Tactical Systems Inc would supply tens of thousands of “M933A1 120mm High Explosive Mortar Cartridges and related equipment”.

Gallagher, the researcher, said Canadians would likely have never known that the weapons were bound for Israel if the US government hadn’t revealed the information itself.

“Because these [weapons] are being sent through the US to Israel, these will almost certainly face no regulatory oversight by Canadian officials,” he said.

“And in addition to that, they will not be included in Canada’s official reporting of its arms exports to Israel,” Gallagher continued. “These will be off the record, except from this reporting from the DSCA.”

The announcement also came as Canada — along with other Western countries that provide military support for Israel, most notably the US — is facing growing calls to impose an arms embargo on Israel amid the Gaza war.

After Canada’s Parliament passed a non-binding motion in March urging a suspension of arms transfers to Israel, Canadian Foreign Minister Melanie Joly said the government would not authorise any new permits for weapons exports to the country.

But rights advocates quickly questioned why existing permits weren’t also being revoked, and some asked how the government’s pledge would affect transfers of weapons to the US that do not require permits, yet could end up in Israel.

Canada’s foreign affairs department, Global Affairs Canada, did not respond to Al Jazeera’s questions about the US government’s announcement in time for publication.

Henry Off, a Toronto-based lawyer and board member of the group Canadian Lawyers for International Human Rights (CLAIHR), said the news highlights “how flawed [Canada’s] arms export system is”.

It demonstrates “how easily [arms] can end up in Israel just because they can go through the United States”, he explained.

Off’s group is currently involved in an ongoing lawsuit against Joly, demanding an end to Canadian weapons shipments to Israel.

“Canada is legally obligated not to allow these transfers,” he told Al Jazeera.

“We know that these arms and weapons parts are used to commit serious violations of international humanitarian law and human rights law, and this is just another example of how Canada has failed to meet its international legal commitments and its domestic legal commitments.”

‘Hold both US, Israel accountable’

Canada’s involvement in the supply of weapons to Israel has also drawn concern from Palestinian rights advocates in the US who say they have tried for months to get the administration of President Joe Biden to stop sending arms — to no avail.

The US provides $3.8bn in military assistance to Israel annually, and Biden’s administration has approved additional weapons sales and other aid to the country several times since the Gaza war began in early October.

Raed Jarrar, advocacy director at Democracy for the Arab World Now, a Washington-based think tank, said the US is violating its own laws by refusing to stop the arms transfers despite evidence they are being used in Israeli rights abuses against Palestinians.

Israeli forces have dropped American-made bombs on Gaza over the course of the war, according to investigations by US media and rights groups, killing scores of Palestinian civilians.

“The United States has lost its moral capital. It has lost its political capital and its leadership when it comes to its blind support to Israel,” Jarrar told Al Jazeera. “And Canada cannot rely on US mechanisms for accountability.”

He said authorities in Canada should step in to ensure that no weapons and equipment manufactured by Canadian companies are contributing to abuses against Palestinians.

“All countries, including Canada, have a moral, ethical and legal obligation to disrupt the supply chain of genocide,” Jarrar said.

“As an organisation based in the United States, I can confirm we have done everything possible to convince our government to adhere by our law, by international law — and we have failed,” he concluded.

“The same way that Israel is unable to hold Israel accountable, the United States is unable to hold the United States accountable. It is time for other countries to hold both Israel and the United States accountable.”