Popular Consent and the Authority to Declare War: A Republican-Kantian Account of Just War Theory

This paper asks whether a war can be justified when it is initiated without the explicit consent or consultation of the people. Drawing on the republican tradition’s emphasis on non-domination and Kant’s conception of rightful political authority, the article develops a normative framework for assessing the legitimacy of war in the absence of popular consent. From a Kantian perspective, a state’s authority is derived not from direct democratic assent in each decision, but from its standing as a public legal order oriented toward freedom, equality, and independence. At the same time, Kant observes in Perpetual Peace that in a republican constitution the people must be asked for their consent to go to war, and would therefore be reluctant to authorize it, since they bear its burdens. This claim highlights the republican demand that political power remain subject to popular control in order to avoid domination. Yet the paper also confronts two challenges to this tradition. First, the problem of republican warmongering evident in historical cases where republican or representative regimes have mobilized patriotic identity, civic virtue, or expansionist ideology to legitimate aggressive warfare, raises doubts about whether popular accountability is sufficient to restrain militarism. Second, the problem of democratic tyranny shows that even formally participatory or majoritarian systems may authorize unjust wars. Bringing these difficulties into dialogue with Kant’s account of rightful political authority, the paper argues that the justice of war depends not merely on the presence of popular assent, but on whether the institutions authorizing it secure citizens’ status as co-authors of the law under conditions that prevent domination both by rulers and by majorities. Wars initiated by unaccountable or arbitrary leaders fail this criterion, but so too do wars produced through democratic processes that operate without adequate safeguards against collective arbitrariness. In light of emerging forms of technologically mediated conflic (such as cyber operations, hybrid warfare, algorithmic targeting, and the accelerated executive decision-making) the paper clarifies how Kantian-republican criteria for rightful authority apply when war-making becomes less visible, less deliberative, and less democratically controllable.