The Guarded Peace

Abstract

The relationship between a nation's military and the peace it professes to seek is among the oldest and least settled questions in the study of statecraft. This article examines that relationship across three analytically distinct functions: the defense apparatus as a standing institution of peace, military deterrence as a mechanism of peacekeeping, and the direct use of military force in the creation of peace. Drawing on the classical canon from Vegetius, Kant, and Clausewitz through the deterrence theory of Schelling and Jervis, and on the contemporary quantitative literature on peace operations, the article argues that military power and peace are neither opposites nor equivalents but are structurally interdependent. A professional, civilian-controlled defense apparatus stabilizes the state that maintains it, credible deterrence raises the expected cost of aggression and thereby preserves a negative peace, and force applied under legitimate mandate can create the security conditions in which a positive peace becomes possible. Each function, however, carries a corresponding pathology: militarization, the security dilemma, and the conflation of military victory with political settlement. The article concludes that the military instrument is a necessary but insufficient condition of peace, and that its contribution depends on its subordination to diplomacy, law, and sustained civilizational dialogue.

1. Introduction

Every state that seeks peace maintains an instrument built for war. This paradox, ancient in origin and contemporary in urgency, frames the inquiry of the present article. In 2025, world military expenditure reached 2,887 billion United States dollars, the eleventh consecutive year of increase and the equivalent of 2.5 percent of global economic output, the highest such share since 2009 (SIPRI 2026). During the same period, the United Nations (UN) maintained eleven active peacekeeping operations on four continents, each of them staffed principally by soldiers (United Nations 2026). The nations of the world, in short, are spending more on their militaries than at any time in the modern era while simultaneously deploying those same militaries, under national and international mandates, in the service of peace. Any serious account of contemporary international order must therefore explain how the armed forces of a nation relate to the peace that its diplomacy pursues.

The argument of this article proceeds from a simple premise: military power and peace are neither opposites nor equivalents. They are structurally interdependent, and the character of that interdependence varies with the function the military instrument is asked to perform. The article distinguishes three such functions. First, the defense apparatus operates as a standing institution of peace, ordering the state's capacity for violence, professionalizing its custodians, and extending the state's diplomatic reach through military-to-military engagement, humanitarian assistance, and security cooperation. Second, the military operates as an instrument of deterrence, preserving peace not by acting but by making credible the promise of action, and thereby raising the expected cost of aggression above the expected gain. Third, the military operates as an instrument of peace creation, whether through the interposition of peacekeepers between former belligerents or through the direct application of force to end atrocity, enforce settlement, or defeat an aggressor.

Each of these functions has generated its own body of scholarship, its own historical record, and its own characteristic pathology. The sections that follow examine each in turn. Section 2 establishes the conceptual foundations, drawing on the distinction between negative and positive peace and on the classical literature linking military preparation to political order. Section 3 examines the defense apparatus as an institution, with particular attention to civil-military relations and defense diplomacy. Section 4 analyzes deterrence as a means of peacekeeping, together with the security dilemma that shadows it. Section 5 examines the use of force to create peace, from consent-based peacekeeping through peace enforcement and humanitarian intervention. Section 6 draws the threads together and considers the implications for the practice of diplomacy and for the dialogue among civilizations that this journal exists to advance.

2. Conceptual Foundations: Peace, War, and the Armed State

Any analysis of the military's relationship to peace must begin by specifying what is meant by peace. Johan Galtung's foundational distinction remains the most serviceable. Negative peace denotes the absence of direct, organized violence; positive peace denotes the presence of the structures, institutions, and relationships that make violence unnecessary (Galtung 1969, 183). The distinction matters for the present inquiry because the military instrument bears on the two forms of peace in radically different ways. Armed force can produce and preserve negative peace directly, by defeating, deterring, or separating those who would use violence. It can contribute to positive peace only indirectly, by creating and holding open the space in which political, economic, and social reconstruction may proceed. Much of the confusion in public debate about the military and peace dissolves once this distinction is held firmly in view.

The classical tradition understood the connection between preparation for war and the preservation of peace long before modern social science formalized it. The Roman military writer Vegetius rendered the proposition in its most durable form: he who desires peace should prepare for war (Vegetius [ca. 390] 1996, 63). The insight is not a celebration of militarism but a claim about incentives, namely that weakness invites predation and that visible strength discourages it. Carl von Clausewitz supplied the necessary corollary: war is never an end in itself but the continuation of political intercourse with the addition of other means, and its conduct is intelligible only in relation to the political object it serves (Clausewitz [1832] 1976, 87). If war is an instrument of policy, then so is the standing capacity to wage it, and the question becomes not whether a nation should possess military power but to what political objects that power is harnessed.

Immanuel Kant, writing in 1795, framed the opposite pole of the tradition. His sketch of a perpetual peace called for the eventual abolition of standing armies, on the ground that their mere existence threatens other states and fuels competitive armament (Kant [1795] 1991, 94). Yet Kant's deeper legacy points elsewhere. The republican constitution, the pacific federation of law-governed states, and the spirit of commerce that he identified as the true engines of peace have become the intellectual foundation of the democratic peace research program (Doyle 1983, 225). Michael Howard, surveying this history, concluded that peace is not the natural condition of mankind but an invention, an artifact of political order that must be constructed and defended, sometimes by force of arms (Howard 2000, 1). The theoretical stage is thus set by a triangle of propositions: preparedness discourages aggression, force is intelligible only as an instrument of policy, and peace itself is an institutional achievement rather than a default state. The three sections that follow examine how the modern nation-state has built upon each proposition.

3. The Defense Apparatus as an Institution of Peace

The most elementary contribution a defense apparatus makes to peace is internal to the state that maintains it. The consolidation of the legitimate means of violence under public authority is constitutive of political order itself, and where that consolidation fails, civil war and predation follow. A national military, properly constituted, does not merely defend the state's borders; it embodies the state's claim that violence within those borders is subject to law. The operative qualification is properly constituted. Samuel Huntington's classic formulation identified the mechanism: objective civilian control, achieved by professionalizing the officer corps and rendering it politically sterile, simultaneously maximizes military effectiveness and secures the military's subordination to civil authority (Huntington 1957, 83). Where professionalism and civilian control are absent, the defense apparatus becomes a threat to the peace of its own society, a lesson written across the history of coups and military governments on every continent, including the histories that both the United States and Brazil have had occasion to study in their respective hemispheres. The first peace a military secures, in short, is the domestic peace of constitutional order, and it secures that peace precisely by accepting its own subordination.

Beyond the state's borders, the defense apparatus functions as an instrument of reassurance and relationship. The practice now commonly called defense diplomacy encompasses military-to-military exchanges, combined exercises, professional military education for foreign officers, security cooperation agreements, and the routine contact of defense attachés. These activities build what armed force alone cannot: transparency, habits of communication, and personal trust between the officer corps of different nations. Joseph Nye's account of soft power, the capacity to obtain preferred outcomes through attraction rather than coercion, applies with particular force to these programs, through which a nation's military becomes an ambassador of its professional standards and constitutional values (Nye 2004, 5). An officer who has trained alongside a foreign counterpart, studied at a foreign staff college, or planned a combined humanitarian exercise carries into any future crisis a channel of communication that no formal démarche can replicate.

The defense apparatus likewise serves peace through missions that involve no adversary at all. Humanitarian assistance and disaster response have become core military competencies because no civilian institution can match the military's capacity for rapid logistics, heavy lift, field medicine, and engineering under austere conditions. Naval hospital ships, airlifted relief supplies, and engineer battalions restoring roads and bridges after earthquakes and hurricanes represent the military instrument applied directly to human welfare. These missions are not incidental to the military's purpose. They demonstrate that the organized, disciplined capacity a nation builds for war is convertible, at need, to the service of life, and they accumulate goodwill that outlasts the emergency that occasioned them.

Two cautions attend this institutional portrait. The first is fiscal and social: the resources devoted to the defense apparatus are resources unavailable to other public purposes, and a level of armament appropriate to one security environment may constitute militarization in another. The eleventh consecutive year of rising world military expenditure (SIPRI 2026) obliges every government to ask whether its defense establishment remains proportionate to the threats it faces. The second caution is institutional: a defense apparatus contributes to peace only so long as it remains an instrument of policy rather than a maker of it. The health of civil-military relations is therefore not a domestic housekeeping matter but a variable of international consequence, for a military that answers reliably to constitutional authority is a military whose signals other nations can read and trust.