This chapter starts by reviewing three historical cycles of political violence in Canada. The cycles include revolutionary war; demands, claims and condemnations; and glocalisation. The chapter provides an overview of counterterrorism structures and activities, with special attention given to the interactions between political violence and its policing. Various counterterrorism agencies in Canada, and in particular the Royal Canadian Mounted Police (RCMP) and the Canadian Security Intelligence Service (CSIS), have seen their legal powers and budgets significantly increased. The "CSIS era" of counterterrorism begins with the most spectacular failure in Canadian high policing: despite having identified and listened in on conversations between Sikh extremists, and followed some in the woods where they tested a bomb. Policing the problem of political violence, then, should be about more than finding and watching terrorists plot an attack or arresting, at the airport terminal, a few youths who have decided to take part in a foreign conflict.