The Roosville Incident
The Canadian parliament's enaction of the radical Paulsen Program in 2017 created what some observers described as the largest shift in military capacity seen on the North American continent since the last century. Over the next five years, a gradual strengthening of Canada's borders and its overt military capacity, in the face of economic pressure from its southern neighbor, led to the virtual fortification of the country.
However, the tide of migrants from the United States displaced by economic collapse continued to grow, and these illegal immigrants - nicknamed "snowbacks" - became a major issue for cities along the border.
It was this charged political environment that would lead to a bloody skirmish when, in the winter of 2020, officers of the RCMP used lethal force to deter a horde of American economic refugees from crossing the Montana/British Colombia border near the town of Roosville.