This article provides a comparative analysis of the constitutional constraints on Canadian government decisions to use military force, and makes theoretical and normative arguments for change. It examines how, in contrast to a trend among constitutional democracies, the executive power in Canada has particularly unfettered discretion to engage in armed conflict under the Royal Prerogative. This article, grounded in theories on deliberative democracy, the democratic peace, and the constitutional incorporation of international law principles, argues against such an expansive executive role. It advances reasons for narrowing the Royal Prerogative, with the development of a greater parliamentary role in the decision-making process, the establishment of clear and increased constitutional limits on the conditions under which the government may engage in armed conflict, and thus narrow grounds for potential judicial review of decisions that depart from the process.