India and Canada have engaged in tit-for-tat diplomatic expulsions as part of an intensifying row over the killing of Hardeep Singh Nijjar, a Sikh separatist, on Canadian soil.

The 45-year-old came to Canada as a refugee decades ago and had since became a Canadian citizen. He was an ardent advocate of establishing a sovereign state of Khalistan, a Sikh homeland in India's Punjab region.

Canada's Prime Minister Justin Trudeau claims that Indian agents were involved in the murder of Nijjar. India dismissed the allegations as "absurd." However, Indian officials view Nijjar as a terrorist, a member of the banned Khalistan Commando Force, whom India links to targeted killings of various political and religious figures.

No threat to India's unity

While the accusations from Prime Minister Trudeau are likely to further strain relations between the two nations, the row has also brought renewed focus the issue of Khalistan. Some in India fear a revival of militant Sikh separatism that once threatened to tear the country apart.

Pockets of Punjab are also afflicted by social problems such as a drug epidemic and unemployment. But a senior Indian intelligence official told DW there is not much to worry about.

"There is currently no unrest in Punjab, one of the country's most successful states. Khalistan is not a threat to India's unity, but it could affect its foreign policy because of the sharp rhetoric of the community living abroad," he told DW.

"All mainstream political parties, including in Punjab, have denounced violence and separatism," the official added.

Millions of Sikhs abroad

The Sikh separatist movement has long been a source of tension in Canada-India ties. Canada is home to the world's largest Sikh diaspora, comprising of about 800,000 people, which is roughly 2% of its population. Some 3 million Sikhs are estimated to live outside India, mainly in the UK, the US, Australia, and Canada.

The movement to create an independent Sikh nation, known as Khalistan, led to the killing of tens of thousands of people in the 1980s and 1990s. The violence was inspired by radical preacher Jarnail Singh Bhindranwale.

An especially traumatic event for the Sikh community was the storming of the Golden Temple — the holiest shrine for Sikhs — in 1984. Indian security forces allegedly hoped to capture Bhindranwale in a surgical strike, but the operation went awry after they encountered resistance. Officials say hundreds of lives were lost, but Sikh activists claim the death toll was much greater.

Additionally, Sikhs around the world were incensed that their sacred place was violated by police action and former Indian prime minister Indira Gandhi was assassinated in retaliation by Sikh members of her own bodyguard.

Since then, India has outlawed the Khalistan movement and groups associated with it are listed as terrorist organizations under the terror law, the Unlawful Activities (Prevention) Act.

Radicalization easier outside India

Sikh organizations say there is no consensus on the support for Khalistan even if it might have traction amongst the diaspora.

"Sikhs in Punjab and those settled in other parts of the country do not support a separate Khalistan," Partap Singh, secretary general of the Sikh Forum in Delhi, told DW. At the same time, Sikhs feel hurt and have "serious grievances," for the way they've been treated after the India-Pakistan partition, he added.

"There is a need for long awaited healing by political dialogue with full understanding and compassion instead of the use of unethical techniques and forces in spreading hatred against Sikhs," added Singh.

Pramod Kumar, director of the Chandigarh based Institute for Development and Communication, who has studied the issue closely, points out that radicalization of Sikhs was pre-dominant among the community abroad.

"Sikh terrorism is not about to erupt again in Punjab and does not have the legs. The diaspora abroad tries to give it moral muscle," Kumar told DW.

Khalistan 'without bombs and bullets'

He cited the detainment of Amritpal Singh, a radical separatist from Punjab who was the target of a weeklong manhunt before reportedly surrendering in April this year. His activities raised fears of a resurgence of militant Sikh separatism.

"He anointed himself leader of Waris Punjab De but when he was arrested, it did not prompt significant protests suggesting there was little support. That should have settled the matter," said Kumar.

Still, many Sikh organizations in Punjab remain wary of the future. The latest incident in Canada has forced the Shiromani Gurdwara Parbandhak Committee (SGPC), which manages Sikh places of worship, to express "serious concern" over the allegations levelled by Trudeau against India over the killing of Nijjar.

The organization also strongly condemned what they see as hate propaganda against Sikhs and Punjab by a large section of the media.

But Nijjar's death has apparently struck a different chord with the pro-Khalistani organization Dal Khalsa. After news of Nijjar's death was first reported in July, the Dal Khalsa held a protest march, and many of its activists were arrested.

Its spokesperson Kanwarpal Singh told DW about the movement's vision of the future.

"We believe in a Khalistan which is without bombs and bullets. It will be democratic and without bloodshed and violence. This is something which you cannot rob us of," he told DW.

Edited by: Darko Janjevic