Canada’s counter-terrorism strategy, like that of most of its allies, has four parts: prevent, deter, detect, disrupt. Despite wide agreement that prevention is key to a society whose members are resilient against radicalization leading to politically motivated violent extremism, prevention seems difficult to operationalize. In federations – and decentralized systems such as Spain’s – the task is further complicated by the division of powers and autonomous or overlapping jurisdictions. This presentation reviews the types of personalities that appear to be particularly prone to engaging in politically motivated violent extremism. It then compares some of the more prominent prevention and early-intervention programs across the United Kingdom, Belgium, the United States and Canada, and, in the process, identifies important commonalities and differences. The presentation then compares approaches in Toronto, Calgary, and Montreal, all of which have important nuances. The presentation finished on key challenges, including interjurisdictional issues, unfunded mandates, as well as metrics and approaches to evaluating their effectiveness.