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Causes of War: A Theory Analysis

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Causes of War: A Theory Analysis

Kyle Amonson

            “To expect states of any sort to rest reliably at peace in a condition of anarchy would require the uniform and enduring perfection of all of them” (Waltz, 2001, pg. 9).

War and conflict has been as much a constant in human history as humans. As Kenneth Waltz states, “there is no peace in a condition of anarchy,” and there will always be a form of anarchy as long as human nature is a variable in our complex domestic and international systems. Many scholars have analyzed the causes of war on a state-by-state-basis, other writers believe that it is possible to provide a wider, more generalized explanation (Baylis et al, 2017, pg. 239).  Additionally, many well-known international relations theorists have applied forms of theoretical framework to understand how and why we create friction in our societies, focusing on a variety of aspects, from international institutions to gender. For neorealist writers such as John Mearsheimer, international politics is not characterized by these constant wars, but nevertheless a relentless security competition, as we will discuss in this essay (Baylis et al, 2017, pg. 242).

There are many immediate contributing factors of war, and this essay will discuss them, but it will initially focus on the generalized explanation of human nature in the pursuit of security as the primary cause of war. This essay will define war in the international and historical sense, then analyze human nature’s role in conflict, followed by human nature’s projection on the nation state and finally conclude with the most frequent manifestations of conflict and conclusion.

Defining War

“War is nothing but a duel on an extensive scale…war therefore is an act of violence intended to compel our opponent to fulfil our will” (Clausewitz et al, 2008, pg. 12).

In order to understand the causal factors of war we have to define what war is and reverse engineer how and why these parties escalated their relations to a violent level of conflict. War is organized violence among groups; it changes with historical and social context; and, in the minds of those who wage it, it is fought for some purpose, according to some strategy or plan (Baylis et al, 2017, pg. 225). War may seem simple to define yet encompasses a variety of conflicts with many types and forms of war displayed throughout history and modern times. The two most common forms of warfare are high intensity conflict and low intensity conflict. High intensity conflict is defined through concepts consistent with linear warfare, symmetric combat, combined arms maneuver and unified action through multiple domains. This type of warfare is engaged with “near-peer” capable parity between states. Low-intensity conflict is consistent with asymmetric, permissive battlefields, irregular guerilla tactics, counter-insurgency operations and typically involves non-state actors. Within the concept of war as a whole there also exists the concept of “total war,” where a state is fighting for its very existence. Total war is relative to the concept of “limited war,” which is fought for any lesser goal than political existence (Baylis et al, 2017, 228). Additionally war can either be international, involving more than one sovereign state, or a civil war, existing within a state.

Escalating a conflict to a state of war is never a lighthearted decision, regardless of the type and level of violence. By nature, war escalates, each move is checked by a stronger counter-move until one of the combatants is exhausted (Baylis et al, 2017, pg.230). War takes a significant toll on both the economy and the society of the warring nations, often irreparably changing their culture and shaping their politics for years to come. As Clausewitz famously stated:

War is always a serious means for a serious object….Such is War, such the Commander who conducts it; such the theory which rules it. But War is not pastime; no mere passion for venturing and winning; no work of a free enthusiasm: it is a serious means for a serious object (Clausewitz et al, 2008, pg. 30).

Human Nature’s Role

“Wars result from selfishness, from misdirected aggressive impulses, from stupidity. Other causes are secondary…” (Waltz, 2001, pg. 30).

War is a creation of human nature. The psychological variables, feelings, and behavioral traits of humankind are just a few of the wide range of variables that comprise what is the basic human experience. One common trait to all humans in any society is our flaws and the inherent differences established among society that have developed our cultural norms throughout history. While humans are not “hard-wired” for war and destruction, war is a by-product of envy, selfishness, and self-preservation. As Kenneth Waltz stated in his analysis of “the first image” in his book, Man, the State, and War, all “other causes are secondary.” In order for a state to wage war, “the passions which break forth in War must already have a latent existence in the people” (Clausewitz et al, 2008, pg. 33).

Another common trait is the innate need for safety, most easily described through Maslow’s hierarchy of needs. Maslow states that “if the physiological needs are relatively well gratified, there then emerges a new set of needs, which we may categorize roughly as the safety set of needs” (Maslow, 1943, pg. 6). Additionally, Liberty Hobbes stated “everyone in a state of nature fears for his safety, and each is out to injure the other before he is injured himself” (Waltz, 2001, pg. 93). In the field of international relations, prominent theoretical frameworks refer to this need for safety among people groups as the concept of security.

Security most closely resonates in the subjective state of mind of the people group in that given state. As stated by Arnold Wolfers "security, in an objective sense, measures the absence of threats to acquire values, in a subjective sense, the absence of fear that such values will be attacked" (Baylis et al., 2017, pg. 240). One can attempt to quantify state power and military capability as it relates to security, but primarily security is a feeling, often felt as a lack of threat-based anxiety on the individual level.

Regardless of the reason for conflict, human’s arrogance that their morality is the ultimate morality has justified conflict since the beginning of time. St. Augustine of Hippo set a precedence of justifying violence in the sake of the common good, a “common good” that is based on societal norms. The commonly accepted just war tradition suggests that any conflict in the name of an end state of peace is acceptable, based on the tenants of jus ad bellum, jus in bello, and jus post bellum, which all encompass varying levels of subjectivity (Baylis at al, 2017, pg. 215).

Human Nature’s Projection as a State

“A nation is secure to the extent to which it is not in danger of having to sacrifice core values if it wished to avoid war, and is able, if challenged, to maintain them by victory in such a war” - Walter Lippman (Baylis et al, 2017, pg. 240).

In order to understand the causes of war we have to first analyze human nature and the common traits of individuals. But individuals do not wage war, states and non-state actors wage war. These groups of individuals, bound by a common idea that compels them to violence, represent the human condition that projects on a state to cause conflict. As stated by Waltz in his second image, “men live in states, so states exist in a world of states,” explaining that states mimic human nature, and the international community subsequently mimics states (Waltz, 2001, p. 20). International relations scholars have applied frameworks to war to assess its root cause and have distilled a variety of conclusions. Realism focuses on ideology based on the pessimistic school of thought that human nature will inevitably lead to war while attempting to develop power to support a state's national interests. Realists believe no one can be trusted to protect your state but yourself, security can only be guaranteed through self-help, and regardless of a state's personal goals, the one common interest is survival. Additionally, neorealists focus on the anarchical concept of states existing in a community lacking central authority, where nationalism and security competition leads to inevitable conflict.

Liberal theorists believe that because of the inherent flaws in human nature that humans project onto states, that states will become less and less relevant, resulting in the increased influence of institutions in conflict. These theorists emphasize the positive consequences of globalization in creating deepening interdependence and spreading prosperity, thereby reinforcing global stability (Baylis et al., 2017, Page 30). Liberal institutionalism focuses on the major role that institutions and non-state actors play in international relations and their capability of mitigating security competition through the concept of collective defense. Marxists point towards conflict generated through social divides and class friction, on a domestic and international scale while constructivists focus on the social and cultural variables.

 A consistent narrative in many major theories is the emphasis of the basic need for security. Clausewitz stated that “as long as the enemy is not defeated, he may defeat me; then I shall no longer be my own master” (Clausewitz et al, 2008, pg. 15-16). This type and level of fear continues the perpetual security competition. Inherent to this competition is that, regardless of the level of state aggression, an increase in security by one state is perceived as a decrease in personal security by another. One example of this in recent history is nuclear proliferation. Our text confirms that the "globalization has also facilitated the proliferation of weapons technologies, including those associated with weapons of mass destruction (WMD)" (Baylis et al, 2017, pg. 250). These WMDs have directly resulted in the continued escalation of security competition, evident in events such as the Cold War. Each increase in capability directly creates a perceived decrease in rival states security climate. This competitive technological cycle has been present ever since the start of conflict as stated by Clausewitz, “the necessity of fighting very soon led men to special inventions to turn the advantage in their own favor” (Clausewitz et al, 2008, pg. 90).

What we have therefore established is a security-based cycle, which is bound to the subjective feeling of safety within the individuals and culture of the represented state. This has effectively continued to affirm conflict as both a form of international relations and a political tool. War will continue to be of the oldest and most common forms of international relations…war is both older than the sovereign state and likely to endure into any globalized future (Baylis et al, 2017, pg. 223).

Similar to Maslow’s hierarchy at the individual level, states feel as though they cannot focus on developing their ideal society until security is assured. Once security has been established, a civil society can begin (Baylis et al., 2017, Page 108).  In addition to this cycle of security competition, and the coinciding arms race, states have historically utilized the theory that they can attain security through offensive action to prevent future conflict. Pre-emptive war is as ingrained in war far as back as Sun Tzu’s ancient military strategies. Around 500 B.C. Sun Tzu stated that “standing on the defensive indicates insufficient strength; attacking, a superabundance of strength” (Tzu, 1910, pg. 68). States would consistently rather conduct conflict away from their civilian populace, on their terms, when conditions permitted.

Manifestations of Conflict

Accepting that human nature’s inherent requirement for safety is projected onto the state, thus driving security competition through weapon development, pre-emptive action and power balancing to ensure a state’s ideological continuance, we can further evaluate the manifestations of this friction. However, the secondary motives are typically very different than the primary pursuit of security. Historically, war has revolved around either a society or people group attempting to apply their beliefs to a fellow society, economic or territorial gain and to obtain independence. We will specifically analyze the variables of economic gain, territorial gain, religious ideals, civil war, revolution and pre-emptive war. 

Territorial and Economic Gain

Historically, the pursuit of territory and resources has been one of the most prominent secondary reasons for conflict. The increase in land and the subsequent resources on that land directly correlates to a state’s power, thus increasing the invading states security. As stated by the Athenians to the Melians in Thucydides History of the Peloponnesian War, “besides extending our empire we should gain in security by your subjection,” demonstrating the belief that an invasion to expand territory and conquer people groups enables security (Thucydides, 1810, p. 389).

A modern example would be Russia, who has engaged in illegal annexations in both Ukraine and Georgia for the simple purpose of expanding territory. Related to this example, Waltz states that:

An explanation may be made in terms of geographic or economic deprecations or in terms of deprivations too vaguely defined to be labeled at all. Thus a nation may argue that it has not attained it “natural” frontiers, that such frontiers are necessary to its security, that war to extend the state to its deserved compass is justified or even necessary (Waltz, 2001, pg. 91).


War has historically decided which ideologies dominated (Baylis et al, 2017, pg. 236). The ideologies that have resulted in some of the greatest levels of conflict are those based in religion. The belief in the promise of a specific afterlife has driven people groups to escalate and justify conflict in the name of their ideologies for thousands of year. The desired end state of many of these groups is the secure establishment of a stable society to institute their religion of choice. Just like a government, they need security for stability. The most well know example of religious conflict are the medieval crusades during the 10th – 12th centuries. However, even in modern times religious conflict is still prevalent across the globe.

One prominent example of religious based conflict is the persistence of Islamic extremism in the Middle East through violent non-state actors. Many radical Muslims believe in a society defined by a purified Islam, a return to the Islam “practiced and preached by Mohhammed…in the early 7th century…which would bring with it the diving blessings these early believers enjoyed” (Suarez, 2013, pg. 14). In modern society, these extremists have demonstrated time and time again their willingness to resort to violence to try to achieve this religious goal.

Civil War and Revolution

Marxists, based on the manifesto of Carl Marx, often focus on the domestic conflicts of civil wars that drive states to violence. While their conclusions mostly revolve around class friction it is common for states to have ideological differences within their territorial borders leading to an attempt to establish a majority or revolution through violence. Another significant example of a revolution is the United States’ own Revolutionary War, establishing independence from Great Britain, based on the concept of “no taxation without representation.” In order for the United States to establish their own democracy and create a stable society, based on their ideals, they needed to escalate conflict to the point of war to gain independence.

Even after a revolution is successful or civil war is resolved the lingering ideology may still exist, dormant, in that society, leading to future conflict. Clausewitz stated “even the final decision of a whole War is not always to be regarded as absolute. The conquered State often sees in it only a passing evil, which may be repaired in after times…(Clausewitz et al, 2008, pg. 20).

Preemptive War

One scenario that prematurely escalates conflict is the act of pre-emptive

war. Though a state may want to remain at peace, it may have to consider undertaking a preventive war; for if it does not strike when the moment is favorable it may be struck later when the advantage has shifted to the other side (Waltz, 2001, p. 21). Sun Tzu stated “he will win who, prepared himself, waits to take the enemy unprepared. He will win who has the military capacity and is not interfered with by the sovereign” (Tzu, 1910, pg. 68). Any military strategist knows that seizing the initiative and maintaining tempo and audacity on the offensive is one of the most significant advantages in battle. Often these strategies are elevated to the level of the state, where to ensure security, a state strikes first.


“The art of war is of vital importance to the State…it is a matter of life and death, a road either to safety or ruin” (Tzu, 1910, pg. 46).

States engage in war to satisfy their human need for safety and security. This allows states to establish stable societies where they can live in status quo with their ideology, religion and culture of choice. The human aspect of society directly reflects in the state and the decisions that state makes. The international body of states, operating with the same human aspects, exists in the anarchic community that exists in constant competition for security through balancing power to ensure their continued existence. Alexander Leighton once said "for world peace we must start on the community level" in that we need to understand regional needs before we can appeal to them in the pursuit of peace (Waltz, 2001, Page 67). On analysis of the inherent flaws in human nature, the only way to effectively target the original source of war is to recognize, target and understand the human nature and needs drive humans to create war. The challenge in addressing this human nature circles us right back to the inherent need for safety. Until individuals can be reasonably assured of their safety and security, without the use of violence, we will continue to escalate conflict to war.Donnelly, M. (Ed.). (2012). Critical conversations about plagiarism (Lenses on composition studies). Anderson, South Carolina: Parlor Press.


Baylis, J., Owens, P., Smith, S. (2017). The globalization of world politics: An introduction       to international relations. New York, NY: Oxford University Press. 7th edition. Print.

Marx, K., Engels, F., & Likes, S. (2012). The communist manifesto (Rethinking the western tradition) (J Isaac, Ed.). New Haven: Yale University Press. eBook.

Maslow, A. H., (1943). A theory of human motivation. Psychological Review, 50(4), 370-396. doi:10.1037/h0054346.

Qutb, Sayyid. (1964). Milestones, 2nd ed. Damascus, Syria: Dar al-Ilm. eBook.

Soto, H. (2000). The mystery of capital: Why capitalism triumphs in the west and fails everywhere else. New York: Basic Books. eBook.

Suarez-Murias, A. (2013). "Jihad is the way and death for the sake of allah is our highest aspiration": A narrative analysis of sayyid qutb's milestones. Retrieved from

Thucydides, Smith, W., & Crane, T., Rev. (1805). The history of the peloponessian war: Translated from the greek of thucydides, to which are annexed three preliminary discourses (4th ed./ed., Wol. 1., il., ill, on the life of thucydides. On his qualifications as a historian. a survey of the history). London: W. Baynes.

Tzu, S., Evans, M., & Giles, L. (2017). The art of war. (Knicker bocker classics). Laguna Hills: Race Point Publishing.

Von Clausewitz, C., Howard, M., & Paret, P. (2008). On war. Princeton: Princeton University Press. eBook.

Waltz, Kenneth. (2001). Man, the state, and war: A theoretical analysis. New York: Columbia University Press. eBook.

About the Author(s)

Kyle Amonson is an active duty Army Captain and graduate student at Norwich University studying international relations and international security. Captain Amonson received his commission from Virginia Polytechnic Institute and State University and has deployed in support of various operations throughout Europe and the Middle East. Opinions expressed in his articles are those of the author's and not those of the U.S. Department of Defense or U.S. Army.


I find this essay rather conflicted (pun intended).


Firstly, if Capt. Amonson is going to use the structure of Maslow’s “Hierarchy of Needs” to explore human motivations that drive war, it should be used in its entirety.  Although basic needs (i.e. access to resources and security) are important, the human needs to belong, for self-esteem, and for self-actualization should not be discounted.   In fact, the drive to satisfy these more advanced or higher needs is invariably found in war, and these motivations tend to attract more support for war among a population than appeal to basic needs.  Despite the economic and security rationales behind the German war effort in the Second World War (creating a fully self-sufficient/autarkic and secure German Empire in Eurasia), Germany fought the war on a primarily ideological basis and regarded both the final victory and final solution as the actualization of Germany as a nation.  During the American Civil War, the abolition of slavery became the “Higher Object” that motivated the United States to fight for total victory and overcome a lack of morale, poor tactical leadership, and both confusion and dissension regarding the aims of the war as well as the war itself.  Even during the Second World War, when the rather obvious need to survive should have been the prime mover, the Allied states motivated their populations by appeals to these higher needs (e.g. Churchill’s rousing speeches, Stalin’s “Great Patriotic War”, the American “Why We Fight”).  In addition, the Western Allies glossed over their differences with the Soviet Union and Soviet collaboration with Germany for the first two years of the war, despite the basic necessity of cooperating with rivals and adversaries in the interests of security.  In addition, one cannot dismiss the romance of war for individuals who had not served or for those who had and were exhilarated by it (e.g. Churchill, again): military service fulfilled many men’s needs for belonging, self-esteem, and self-actualization.  Rather than see Maslow’s hierarchy as a pyramid, perhaps a more dynamic perspective is required...


Secondly, the historical references in this essay are rather cursory.  Russia did not invade Georgia or Ukraine for territorial expansion, and Georgia was invaded as part of a counteroffensive against a Georgian attack on South Ossetia.  In both cases, Russia wanted people not territory, and additionally it sought to prevent the incorporation of either country into Western security (NATO) or supranational (EU) structures.  I find it curious that Capt. Amonson refers to the Crusades in the 10th to 12th Centuries, but not the Muslim Conquests of the 7th to 8th Centuries, which ended six-hundred or more years of Christianity, twelve-hundred years of Judaism, and millennia of other Mediterranean and Near Eastern belief systems. The Mediterranean was the center of the West and of Christendom until the Muslim Conquest, with the northern coast of Africa, Egypt, the Levant, and Mesopotamia as integral as Iberia, Italy, Greece, and Anatolia; and Alexandria, Antioch, and Jerusalem as integral as Rome and Constantinople. 


Thirdly, there should be a distinction made between ‘power to’ and ‘power over’.  There is a difference between waging a war in self-defense (e.g. against external invasion or internal oppression) or self-determination (e.g. independence, freedom), and waging a war to impose oneself on others, whether foreign or domestic.  The contemporary popular narrative of Islamism is curious in this regard as Muslims are perceived as victims of Christian European empires, when in fact Muslim empires were fierce competitors for superiority if not supremacy, and only ceased being a state threat to the West in the early 20th Century.  Both secular Arab Nationalism and Islamism are in fact responses not to oppression by the West, but to the loss of empire.  In Northern Ireland, the Catholic Republicans included: separatist supremacists who wanted a united Ireland where Protestant Unionists were subject to tyranny of the majority; separatist egalitarians, who wanted a united Ireland with equal treatment for all; and integrationist egalitarians, who wanted equal treatment whether in a united Ireland or as part of the UK.  Eventually, the “Troubles” came to an end after some thirty years due to appeal to the integrationist egalitarians, who were the vast majority of Catholic Republicans, who had campaigned unsuccessfully for equal treatment prior to the “Troubles”, and whose verifiable oppression had driven the formation of non-state militant organizations (e.g. the PIRA, INLA, etc.).  Yet Muslims are not and have not been subject to verifiable oppression by the West, and in fact it is Westerners themselves who are integrationist and egalitarian.  At best Islamists want to be separate but equal; at worst they want to be supreme (i.e. ‘power over’).