The classical inquiry
War is the oldest theme in Western literature. The Iliad is the foundational text and the classical philosophical tradition is in part a long argument with it: an inquiry into what war reveals about a person and a polity, what the soldiers should be like, when a war is rightly fought, and what — if anything — peace consists in beyond the absence of war.
The Greek historians made war the central subject of historical writing. Thucydides on the Peloponnesian War (the classical study of the political and human dynamics of a long, ruinous conflict), Xenophon's Hellenica and Anabasis, and later Polybius on the rise of Rome are read together as the early canon of the historical treatment of war. The philosophers handle the question from a different angle: Plato in the Republic on the education of those who fight, Aristotle in the Politics on whether the regime is constituted for peace or only for war.
The just-war tradition
The Christian jus ad bellum / jus in bello tradition is the long attempt to give moral structure to war as a practical reality. Augustine in the City of God and the letters opens the question of when the use of force can be compatible with right rule; Aquinas in the Summa Theologiae lays out the classical conditions of a just war (legitimate authority, just cause, right intention); Grotius in De Iure Belli ac Pacis (1625) is the early-modern foundation of the modern law of war and of international law more generally. The contemporary tradition (Michael Walzer's Just and Unjust Wars is one widely-cited starting point) continues the argument.
Why it matters for Virtue & Power
War is not a metaphor on this platform. It is a recurring, specific human reality with causes that can be examined, and the texts that have examined it best — from the Iliad through the Greek and Roman historians to the Christian and modern theorists — are part of what serious thinking about politics is responsible for.
The site has a separate section page on War & Peace that reads the same inquiry as a study and points outward into the historians and theorists.