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Key Drivers and Motivations That Lead To Interstate Wars


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Interstate wars involve states depending on the military to achieve goals that ordinarily would not have the military involved(Vayrynen, 2013). The key drivers and motivations behind interstate war can be fundamentally categorized into two – rational and irrational causes. Rational causes involve actors of war whose endeavor is to maximize the payoffs in light of the available options. On the other hand, irrational causes involve actors of war whose drive is other factors other than maximizing payoffs in light of the available options. An aggressor before deciding to declare war must be cognizant of the potential costs and benefits(Vayrynen, 2013). Ideally, the benefits of war should outweigh the cost of war, which is observed by a rational actor. However, an irrational actor overlooks this aspect and will declare war based on other drivers apart from costs and benefits. Rational causes that lead to interstate wars include commitment problems, acting based on preventive purposes, asymmetry of information and acting based on preemptive purposes. On the other hand, irrational causes that lead to interstate wars include religion, ethnic cleansing, and revenge.

Commitment problems arise where two states commit to an agreement but then one state feels that the other state will dishonor the agreement (Levy & Thompson, 2011). An agreement can take the form of future transfers and/or not attack the future. The distrust among the states ensues where one country is not guaranteed that the counterpart will abide by the agreement and stop to attack once the stake is transferred or the counterpart will dishonor the agreement and demand for more stake, failure of which the counterpart attacks. A classic example of a commitment problem is the Munich Agreement of 1938. In the absence of the Czech Republic, a treaty was passed authorizing Germany to capture border towns of the Czech Republic that were predominantly occupied by Germans. The treaty only allowed Germany the annexation of Czech Republic but after a while, Germany contravened the treaty and captured the entire Czech Republic (Kennan, 2015). Despite Germany eventually conquering the Czech Republic, the latter state reiterated to counter Germany advancement into their land resulting in an interstate war.

Interstate war based on preventive purposes transpires where balance exists between two countries but only in the short run thus one country fears that an opponent country is likely to become influential in future (Cashman & Robinson, 2007). Such a development may result to disequilibrium among the two countries that are in truce thus one country opts to attack today than waiting to be attacked by a stronger opponent in future. Preventive wars also transpire where one state has arms advantage and anticipate their counterpart could catch up in future thus the former opt to attack while the odds are still in their favor. A remarkable example is the cold war between the United States and the then Soviet Union. A debate rages on whether or not the United States should have engaged the Soviet Union in the early period of the war since the former had more nuclear weapons than the latter (Cashman & Robinson, 2007).

Asymmetry of information can lead to interstate wars. It entails a country overestimating its allies and underestimating its adversaries (Cashman, 2013). A country can overemphasize the military powers of its allies leading it to declare war against its adversaries. In this case, a bargaining failure is likely to ensue since the country intending to declare war feels that the material gains from the war will outweigh the material losses. Similarly, a country may undervalue the military powers of an opponent. Undervaluing an opponent drives a country to fight a war against another in the hope for an easy conquest. However, the actor is not always able to achieve an easy conquest whereby the enemy could have more military power than envisioned. An adversary could also rely on the military powers of allies which an actor may not be aware. A case in point is the American Revolutionary War. In the American Revolutionary War, the Northern colonies fought a war against the Great Britain. The Great Britain did not anticipate that the colonies would win the war since they had limited military power. However, France and Spain supported the Northern Colonies by providing them with ammunition and other weapons. Consequently, the Northern Colonies won in the American Revolutionary War causing Great Britain to retreat south (Cashman, 2013).

The natural anarchy existing among states usually informs a first-strike advantage (Vayrynen, 2013). A surprise attack provides a considerable advantage to an aggressor. In the absence of a first strike advantage and perfect knowledge about the outcome of war, then countries would be willing to engage in bargaining leading to a better allocation of resources. The agreement would be self-enforcing since both countries obtain a higher pay-off by not engaging in war. However, this is not often the case since the outcome of a war predominantly depends on who starts a war. A prime example of a preemptive war is Schlieffen plan which was an operational plan by the German general of staff to attack France (Ehlert, Epkenhans, Gross & Zabecki, 2014). While France was a strong opponent, the general of staff envisioned that a surprise attack would give Germany an advantage since it would take France and its allies a significant time before organizing their troops.

Interstate wars can also be caused by religious differences. The drive behind a war might be to increase the followers of a given religion or to decrease the followers of another religion. The aggressor does not act based on material gain but claims to act on behalf or to appease a higher deity (Eckstein, 2007). Thus, even if there are viable bargaining opportunities, no agreement can stop the aggressor from engaging in interstate war. Prime examples of interstate wars caused by religious differences include the Crusades and the 30-year war (Eckstein, 2007). The Crusades encompass a series of religious wars by Christians against Muslims between the 11th and 15th century (Latham, 2011). The first Crusade involved Christians from Western Europe who invaded Muslims in the city of Jerusalem and captured Jerusalem (Eckstein, 2007). The subsequent wars involved wars between Muslims and Christians whereby the former vowed to fight a holy war (Jihad) in retaliation and also repossess the region forcefully taken from them. Similarly, the 30-year war involved a war between Catholic Christians and Protestants in Central Europe between 1916 and 1948 (Eckstein, 2007). The election of a new Holy Roman Emperor into power led to the war. The Emperor who was a devout Catholic imposed Roman Catholicism on all his subjects. The people in Northern Europe who were Protestants felt that the Emperor had contravened their right to worship. Consequently, the 30-year war between Catholics and Protestants ensued that quickly advanced to a war between the great powers – Central Europe and Northern Europe (Wilson, 2008).

The need for ethnic cleansing can also lead to interstate wars. Ethnic cleansing involves one ethnic group killing another ethnic group (Cashman, 2013). Consequently, that ethnic group immediately becomes more populated today or in the future than the other ethnic group. A war based on the need for ethnic cleansing is largely driven by emotion as opposed to reason thus no amount of agreement and commitment can be used to stop the war. A classic example of a war that can be explained by the need for ethnic cleansing is the Second World War. Hitler felt that his race was superior to other races thus intended to kill people of other races, especially the Jews and have his race dominate (Cashman, 2013). This explains why no amount of concessions could stop the annexation of Germany into other countries.

Revenge is another irrational cause of war. Anger informs revenge whereby an actor declares war on an adversary based on a past action(Lebow, 2010). War driven by anger causes unfathomable damage since no amount of negotiations and agreement can make an actor to end the war. A classic example is the First World War that formed a solid base for the Second World War. Initially, the Germans fought Napoleon and conquered Paris, the capital of France. About four decades later, France fought a war against Germany and reclaimed Alsace-Lorraine from Germany during the First World War. It was during the Second World War that Adolf Hitler declared that the Jews were responsible for the loss evidenced in the First World War and brought Germany to hate France (Wimmer & Min, 2006). Based on the need for revenge, the Second World War materialized whereby scores of civilian and military lives were lost.

It is evident that interstate wars are caused by several factors which can be categorized as either rational or irrational. While rational causes entail an aggressor acting based on reason, irrational causes entail an aggressor acting based on emotion. As a result, interstate wars driven by rational causes can be mitigated through bargaining and promise to abide by the agreement. On the other hand, irrational causes cannot be eased through bargaining and agreements, but rather the attacked state has to fight back till the aggressor retreats. The establishment of the causes of interstate wars is important to fully understand the interstate wars. Resultantly, appropriate measures can be enacted to mitigate the occurrence of interstate wars in future.
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Cashman, G., & Robinson, L. C. (2007). An introduction to the causes of war: Patterns of interstate conflict from World War I to Iraq. Rowman & Littlefield Publishers.

Eckstein, A. M. (2007). Mediterranean anarchy, interstate war, and the rise of Rome (Vol. 48). Univ of California Press.

Ehlert, H., Epkenhans, M., Gross, G. P., & Zabecki, D. T. (Eds.). (2014). the Schlieffen Plan: International Perspectives on the German Strategy for World War I. University Press of Kentucky.

Kennan, G. F. (2015). From Prague after Munich: Diplomatic Papers, 1938-1940. Princeton University Press.

Latham, A. A. (2011). Theorizing the Crusades: Identity, Institutions, and Religious War in Medieval Latin Christendom1. International Studies Quarterly, 55(1), 223-243.

Lebow, R. N. (2010). Why Nations Fight. New York: Cambridge UP.

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Wilson, P. H. (2008). The Causes of the Thirty Years War 1618–48. The English Historical Review, 123(502), 554-586.

Wimmer, A., & Min, B. (2006). From empire to nation-state: Explaining wars in the modern world, 1816–2001. American Sociological Review, 71(6), 867-897.

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