Carl von Clausewitz is regarded as one of the foremost philosophers of war to have ever lived. A Prussian army officer and veteran of the Napoleonic Wars—including Prussia’s darkest hours during the 1806 Campaign, he lived through exciting military and intellectual times. He lived through the Prussian army reforms after their disastrous defeats at the hand of Napoleon, he lived during the German Idealist epoch of philosophy, and while living a relatively short life, published the consequential and influential book Vom Kriege, or On War.
One of the most important, though short, passages of the book deal with what Clausewitz called the “trinity of war”, which is:
[C]omposed of primordial violence, hatred, and enmity, which are to be regarded as a blind natural force; of the play of chance and probability within which the creative spirit is free to roam; and of its element of subordination, as an instrument of policy, which makes it subject to reason.
There are multiple levels of understanding the Clausewitzian trinity of war and its Hegelian impetus.
At the structural level, the common understanding of the trinity of war is that it is composed of an interlinking tripartite reality. Clausewitz’s use of the term trinity has theological roots; something that good Christians in the 19th century would have recognized though many moderns, with the atrophy of basic theological knowledge, do not. The Christian Godhead, the Trinity, is conceived of three distinct personages nevertheless linked together in a binding unity of love which ties together Father, Son, and Holy Spirit. In the same manner does Clausewitz understand the trinity of war: Three distinct personages or groups, nevertheless bound together (in war) which ties them together and to separate out of or two or all would effectively bring about the collapse of war (much like how separating out any one of person of the Trinity from the Trinity leads to the ruination of the Triune Godhead in Christianity). This tripartite unity is composed of people, state, and military. And there is a dialectical Hegelian progression from the first to the last, much in the same manner of emanation in the Christian Trinity of Father to Son to Holy Spirit in the biblical narratives.
Thus, at the structural level the trinity of war sees war as the binding force that crosses all three structures: the people; the state; and the military. Yet, for Clausewitz, there is a gradual process of emergence to the state and military that emanates originally from the people. The starting point of all war is, then, the people. Because it is from the people that emerged, in political society, the state. Hence the famous one-line quote from Clausewitz that “War is a mere continuation of politics by other means.” In other words, war—that conduct of war—is that “instrument of policy, which makes it subject to reason.” The state can only engage in war, and conducts it war through the instrumental use of the military and military industry, if it has the support of the people. Without this support—the “primordial violence, hatred, and enmity,” war cannot sustain itself because the very genus of war is not sustaining and supporting it. This is what guerrilla wars and other “low intensity” conflicts of the last 200 years have shown; when a people grow tired of the war it doesn’t matter if one of the powers engaged in the war is technologically, politically, economically, and militarily superior to the enemy—the group with the most vigorous support from the people will win out.
At a phenomenological level there is also the trinity of war as explained in the straightforward language. Biologically, Clausewitz’s claim is that the people have a manifested spirit of “violence, hatred, and enmity” which, he says, is “a blind natural force.” It is natural for people to have violent impulses, to be filled with hatred and enmity. Now, Clausewitz doesn’t celebrate this reality; he merely acknowledges its reality. The task of war, at the phenomenological level, is to embody and then orient, or direct/order, this “blind natural force” to something objectifiable. This is what is called the “war aim” in military strategy. Blind force gets one nowhere and in the development of war blind force never achieves victory because victory is premised on achieving the war aim.
Furthermore, the “chance and probability” and free-roaming “spirit” are the soldiers who make up the army. The army that is freest to conduct itself without burdensome bureaucracy is the army that is generally most effective on the battlefield. Thus, we see the primordial thesis of violence, hatred, and enmity converging into the military spirit and construction through instrumentalized reason (dictated by political aims) and military ingenuity and decentralized decision-making rather than relying on cumbersome and specified detailed battle-plans. There needs to be room for individual initiative which allows for a more practical ability to achieve war ends.
There is also a Hegelian dialectic at play in greater detail. Hegelian dialectics has an orthogenetic in conception; it has a teleological purpose. The same is true in Clausewitz’s understanding of war as it relates to the trinity of war. The teleological end of war is “it[s] subject[ion] to reason.” Clausewitz is very much a moral philosopher when it comes to war. He is a realist, so he accepts prima facie the reality of war and that war will happen. However, he is also a moralist. War, when it breaks out, should be subject to reason to prevent the limitation of as much destruction and bloodshed as possible. This limitation of destruction is not directed at military combatants—as the Napoleonic Wars helped show (which altered war with the development of the decisive massed battle)—but the limitation of the destruction of non-combatants and non-combatant property: villages, towns, cities; the countryside; industry; commerce, etc. Thus, part of the teleological end of war is the limitation of bloodshed, violence, and destruction which comes about through the formation of rules of engagement, rules of war, the ordering of blind natural passions to specific targets or aims, etc. All of which helps to limit widespread destruction which, as all know, is harmful. While massed warfare has made military engagements deadlier, the task of war is to limit that destructiveness from non-combatants. Clausewitz’s total war is a total war directed at the enemy army.
The natural force of violence, hatred, and enmity becomes embodied in the state because the state, following Hegel, is simply an embodied reflection of its people. Thus, the state’s enemies will be the enemies of its particular people; the hate and enmity that its people have toward the Other (or if we are follow Schmitt, the state embodied the dialectical impetus of the friend and concerns itself with the identification of the “enemy”). The state, having embodied this blind natural force, now orders it by reason, and the outcome of this ordering of the passions is the military. The military is the final emanation of the natural force of violence, hatred, and enmity but, unlike as it is embodied in the people—which is unordered and simply passion without constraints—the military controls this natural force through the instrumental ordering of impulse by reason which results in the war aim, rules of war, and plans of military conduct, etc.
At a deeper level, the trinity of war therefore is passion, chance, and reason. To use the language of political science, it is representation, conscription, and will. This too mirrors the Christian Trinity insofar that God is usually represented as “The Father”, the incarnation of God—conscription—was that of the Son, and the will of God is the Holy Spirit. Passion is that blind natural force that emanates from the people. It is directed and embodied in the state which gets its health from the passion of the people. In embodying this passion the state now subjects passion to the ordering principle of reason and the outgrowth of this ordering of the passion by reason is the military which manifests itself in will: the will of the people, the will of the political state, and the will of military. But the people also embody the element of chance. There is chance the people join the military (conscription) and there is chance embodied in the people who serve in the military; chance that some are lucky, some achieve remarkable success, etc. Thus, the military, like the Holy Spirit in orthodox Western Christian theology (filioque), is not merely the outgrowth of the state but also the outgrowth of the people. (In Western theology, the filioque clause is the belief that the Holy Spirit proceeds from the Father and the Son rather than just the Father alone as Eastern Orthodox theology maintains; thus the linking of the military as proceeding from the state and the people by Clausewitz again plays to the themes of the Christian Trinity as understood in Western thought.)
The people are, therefore, linked to the military and state. The state is linked to the people and military. And the military is bound up with the state and the people. The trinity is locked together in complete relationship, which is why to knock off one leg is to cripple the entire project of war. The trinity of war is interlinked with itself and through itself; war cannot be sustained unless this trinity remains interlinked with itself and through itself. To break any of the three is to bring about the end of war.
Clausewitz noted that one of the changes of the Napoleonic Wars, thus the beginning of modern war, was the role that the people played in war. Before this it was common to see war as simply seeking the destruction of the military to bring about the end of war. However, one could also destroy the state or break the passion of the people and bring about the end of war too. The 20th century has undoubtedly showed Clausewitz to be right on this account. The toppling of states, like the Russian Empire in the First World War, brought about the end of the war on the eastern front. The breaking of the American peoples’ support for Vietnam ended that war.