The diplomatic relations between India and Canada experienced a significant downturn in 2023. This rift was triggered by a specific, highly sensitive event. The correct answer is the Nijjar assassination.
The diplomatic crisis escalated dramatically after Canadian Prime Minister Justin Trudeau publicly stated in September 2023 that there were credible allegations linking the Indian government to the assassination of Hardeep Singh Nijjar. Nijjar, a prominent Sikh leader and Canadian citizen, was shot dead in Surrey, British Columbia, in June 2023. This accusation led to the expulsion of diplomats and a severe strain on bilateral ties. While trade disputes can cause friction, they were not the primary catalyst for this particular rift. Visa denial and embassy closure were consequences or measures taken during the crisis, not its root cause. The assassination and the subsequent allegations were the direct trigger for the diplomatic breakdown.