Unwritten Ultimate Responsibility: The Prime Minister and Canadian National Security

Canada's Prime Minister is ultimately responsible for national security, yet powers they exercise in this domain are largely unwritten. While statute and regulations provide ministers, departments, and agencies with most of their national security authorities and functions, the Prime Minister's national security functions and powers mostly stem from an interplay of constitutional convention, Crown prerogative, and their capacity as the head of government. This article examines how each of these sources of authority shape the Prime Minister's national security roles and powers. The article then explores the Prime Minister's national security responsibilities and functions work in particular instances. These instances include how Cabinet committees and the PCO have been organized to support the Prime Minister's national security responsibilities, how the Prime Minister is granted access to classified information, the still evolving roles of the Prime Minister's national security and foreign policy advisors, the Prime Minister's involvement in national security diplomacy and military deployments, and the setting of national security budgets. The article concludes with a brief discussion of the limitations of studying the powers of the Prime Minister and national security in Canada.