In this volume of Voices of the CDA, Dr. Youri Cormier contends that Canada’s sovereignty in the Northwest Passage depends less on legal claims or political declarations than on its capacity to exercise command of the sea. Weighing geographic realities, strategic adversaries, and the limits of Canadian naval capacity, his article assesses what it would realistically take to monitor, regulate, and enforce Canada’s interests in the Arctic – and what a credible, multilateral strategy for achieving that must look like.