What to know about the tensions between Canada and India over the killing of a Sikh

The killing of a Sikh separatist activist in Canada — and Canada's accusations that the Indian government was involved — has reignited diplomatic tensions between the two countries.

On Monday, Canadian Prime Minister Justin Trudeau announced that his country's top intelligence agency had identified "credible allegations" linking India to the killing of Hardeep Singh Nijjar, 45, in British Columbia in June. India has denied any role in Nijjar's death.

Canada is home to the world's largest Sikh population outside of India, and discontent has long simmered between Canada and India over Sikh separatism, a movement that has had a bloody history.

This week's events have sent those tensions spiking, as both countries expelled a diplomat, and on Wednesday, the Indian government urged its citizens to "exercise utmost caution" when traveling in Canada.

Here's what to know:

Who is Hardeep Singh Nijjar and what happened to him?

Nijjar was a prominent figure in the Sikh separatist movement, which has long pushed for the creation of an independent Sikh state in India called Khalistan.

In June, Nijjar was shot to death in his truck outside the Guru Nanak Sikh Gurdwara, a Sikh temple where he served as president, shortly after evening prayers. Authorities have not publicly identified any suspects, but say that at least three remain at large.

Nijjar was born in Punjab, a majority-Sikh state in northwest India. He moved to Canada in 1997, according to previous interviews he had given to Canadian news outlets. There, he lived in Surrey, a city in the Vancouver metropolitan area, and worked as a plumber. He was a Canadian citizen at the time of his death.

In India, where authorities are suspicious of Sikh activists living abroad, Nijjar was a government-designated terrorist. He was suspected of involvement in a 2007 bombing and a 2021 attack on a Hindu priest, both in Punjab. Authorities in India had also accused him of recruiting and fundraising for attacks. Nijjar had denied those allegations.

Thousands attended Nijjar's funeral at the temple where he was killed. After his death, his lawyer told the Vancouver Sun that the Canadian Security Intelligence Service had warned Nijjar about credible threats to his life just days before the shooting.

What does Canada say?

On Monday, Trudeau announced in remarks to parliament that Canadian intelligence services are pursuing "credible allegations" that link India's government to Nijjar's killing. He did not detail any evidence of that link.

"Any involvement of a foreign government in the killing of a Canadian citizen on Canadian soil is an unacceptable violation of our sovereignty," Trudeau said. "We are not looking to provoke or escalate. We are simply laying out the facts as we understand them."

Trudeau also said that he conveyed his concerns about the killing "in no uncertain terms" to Indian Prime Minister Narendra Modi at the Group of 20 summit in New Delhi earlier this month.

Canada has announced it would expel India's top intelligence officer based in Canada.

Canada has long been home to a large community of Sikh expatriates, including vocal separatists. That's been a source of tension for India, which has called on Canada to take more action against Sikh activists; Canada has said their activism is free speech.

How has India responded?

India denies involvement. In a statement issued after Trudeau's remarks, its foreign ministry called the allegations of India's involvement "absurd and motivated."

"Such unsubstantiated allegations seek to shift the focus from Khalistani terrorists and extremists, who have been provided shelter in Canada and continue to threaten India's sovereignty and territorial integrity," the ministry wrote. "That Canadian political figures have openly expressed sympathy for such elements remains a matter of deep concern."

Then, in a tit-for-tat move on Tuesday, India moved to expel a senior Canadian diplomat. "The decision reflects Government of India's growing concern at the interference of Canadian diplomats in our internal matters and their involvement in anti-India activities," the ministry said in a statement.

And on Wednesday, the Indian government issued a travel advisory urging caution for Indian nationals living in and traveling to Canada "in view of growing anti-India activities and politically-condoned hate crimes and criminal violence."

What is the Sikh separatist movement?

Sikhs are a religious minority in Hindu-majority India. Sikhs make up about 2% of the population compared to 80% for Hindus; most Sikhs live in the northern state of Punjab.

For decades, some Sikhs have called for the creation of an independent homeland, which would be carved out of Punjab. The movement has long been opposed by the Indian government, which considers it treasonous.

"A subset of the world of Sikhs are behind this movement, and that is what is causing so much anxiety and concern for India," said Neilesh Bose, a professor of modern South Asian history at the University of Victoria in Canada.

Over the years, the struggle has often turned violent. In 1984, when a group of armed militants holed up at the Golden Temple, the Sikh religion's holiest site, then-Prime Minister Indira Gandhi sent armed forces to arrest them, resulting in damage to the temple and the deaths of hundreds or more. (The exact number of deaths is in dispute.)

Later that year, two of Gandhi's own Sikh bodyguards assassinated her in revenge. Afterward, violent anti-Sikh riots spread across the country and left thousands of Sikhs dead. That violence spilled over into Canada, where in 1985 Sikh militant terrorists smuggled a bomb onto an Air India flight that exploded in midair as it flew from Montreal to London. More than 300 people were killed in what remains the deadliest terrorist attack in Canadian history.

In recent years, Modi has steered India toward Hindu nationalism. His government has at times cracked down on the rights and demonstrations of religious minorities in India.

This spring, when authorities began a manhunt for another separatist leader in India, protests spread in Punjab and in Sikh communities around the world. The Indian government cracked down by deploying paramilitary troops to Punjab, arresting scores of protesters and suspending 4G cell phone service across the northern part of the country.

How has the U.S. weighed in?

U.S. officials say they're concerned about the allegations of India's involvement.

"This is a serious matter and we support Canada's ongoing law enforcement efforts," National Security Council spokesperson Adrienne Watson said Wednesday on X, the platform formerly known as Twitter. "We are also engaging the Indian government."

But the spat could put the U.S. in an awkward position. The Biden administration has worked to build a relationship with Modi as part of its strategy to contain the aspirations of China.

This week, Canada said its investigation would draw on the Five Eyes intelligence-sharing alliance, which includes the U.S., the U.K., Australia and New Zealand. Involving the alliance could compromise that China strategy, said Bose.

"That's a very fragile set of relationships that Canada is thinking about," he said. "It may alienate India and India's relationship not only to the Five Eyes, but to the Western world more broadly."

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