Causes of War in International Relations

Although there has been a marked decline in instances of interstate war since the 1950’s, the threat of war is far from obsolete; thus, the incentive to attain a deeper understanding of why war occurs still remains. Ultimately, wars boil down to the failure of at least two states to reach a bargain over a point of contention, which can range in topic from disputed land rights to human rights violations and everything in between. Though both states may have a vested interest in avoiding a costly and potentially lengthy war, bargaining can give way to war for three reasons: information asymmetry, commitment problems, and indivisible goods.

While it may be more comforting to think of war as a solely intentional act that requires a great deal of contemplation and council, wars can begin by accident when a country’s ability and willingness to fight aren’t transparent. When states are forced to estimate their opponent’s resolve, they stand to face grave consequences, especially if they err on the side of underestimation (Frieden et al., 107-108). For instance, although Japan had reason to believe the U.S. would intercede in its efforts to secure a larger foothold in the Pacific, part of their military strategy hinged on the belief that their own soldiers were more resolved to succeed in combat. Japan’s inability to accurately assess the authenticity of the United States’ threat reflects a common source of information asymmetry: credibility. The art of making a believable threat in interstate bargaining is difficult for two reasons. First, credible threats, like wars, are expensive; to distinguish actual intent from cheap talk, states must be willing to invest time, effort, and/or military resources in exchange for credibility (109). This principle is ultimately what led to China’s involvement in the Korean War in 1950. After the U.S. pushed North Korean forces back behind the 38th parallel, the recently-established PRC threatened involvement, should the United States advance into North Korean territory. Although the authenticity of China’s threat was shown in their subsequent contribution of over half a million soldiers, the United States had no prior reasons to heed a warning cheaply conveyed through a third party state’s ambassador (112). Secondly, credible threats are hard to achieve because states may have a vested interest in concealing information. Actors can overcome this barrier by utilizing three tactics: brinksmanship, paying for power, and tying hands. Brinksmanship, demonstrated by the Iraqi army’s presence at Kuwait’s border in 1990 (preceding their invasion and occupation), describes action taken by a state to demonstrate a credible threat, but which consequently brings both states to the precipice of war (106, 113). Paying for power is a similar phenomenon in which states incur large costs associated with expanding military capabilities or bolstering the appearance of resolve, similar to the United States’ commission of several new aircraft carriers in response to Japan’s expanding presence in the Pacific during WWII (116). Lastly, state leaders can enhance the credibility of threats by “tying their hands.” Though arguably more convincing from democratic states with political accountability, tying hands can lessen a leader’s desire to recant prior statements under threat of political backlash or “audience costs,” as demonstrated by President Bush’s adamant declarations that Iraq would face grave consequences if they invaded Kuwait (115).

Wars initiated by commitment problems are also borne out of insufficient credibility. Some interstate negotiations call for authentic promises, rather than authentic threats. When a bargain requires one state to willingly make itself more vulnerable, the other state must demonstrate its resolve to abstain from using its future power for exploitative purposes (119). This dilemma is often at the heart of negotiations over weapons programs. For instance, the Iraq War occurred, in part, because the United States didn’t believe Iraq had followed through on its promise to discontinue the production of WMDs. Although the assumption was incorrect, the United States no longer felt the need to live up to its own side of the bargain, and war ensued (63). While Iraq took the bargain and still faced the consequences, not all states are willing gamble on making themselves more vulnerable in the first place. When states find themselves on the declining side of a shifting power dynamic, some prefer their odds at war now to their odds at peace later on. Preventative war describes a situation in which an actor is compelled to fight now to prevent receiving a less favorable bargain later (122). The United States, though motivated by false suspicions, believed a preventative war with Iraq in 2003 was preferable to a war with higher stakes down the line. Preemptive war, on the other hand, occurs when war and a shift in the power dynamic are imminent (125). One or both actors are compelled to “strike first” to obtain an upper hand not easily secured later on. Japan utilized such a strategy in its attack on Pearl Harbor in 1941, when the United States’ production of aircraft carriers threatened their chances of victory later on. While credibility-enhancing strategies like brinksmanship, paying for power, and tying hands are effective in coercive bargaining, few strategies exist for powerful states to convince other actors they won’t exploit them. For this reason, wars initiated by commitment problems aren’t resolved as quickly as those caused by information asymmetry. Resolve and capability are easily communicated when fighting begins, but mistrust incurred from vulnerability is not easily overcome (124).

Finally, war can occur when states bargain over the rights to an ‘indivisible’ good. When it comes to interstate bargaining, the term ‘indivisible' may not strictly refer to an inability to physically divide a good, like core values, but rather an unwillingness to do so, like disputes over key territories. In international relations, a good is said to be indivisible if an attempt to divide it would reduce its inherent quality or value (127). Disputes over so called ‘invisible’ goods often result in war because the range of bargaining options that typically exists between two states’ ideal outcomes is either greatly reduced or eliminated altogether. For example, the city of Jerusalem is of great religious significance to Jews, Christians, and Muslims, each of whom have sought sole control of the territory under the flags of various tribes, countries, and empires for centuries. Because the locations of each religion’s historical sites are in close proximity, or literally sit atop one another as in the case of the Dome of the Rock, the parties involved remain unmotivated to consider options that involve splitting up or sharing the land, thereby making negotiations a moot point (128). Wars caused by indivisible goods are arguably some of the most frustrating, because they are often more representative of a state’s inflexibility in bargaining, rather than a misunderstanding or inability to reach an agreement. If motivated to do so, states could prevent a costly war by simply devising a means to share the ‘indivisible’ good, or use a negotiation strategy involving issue linkages, where one state offers another a better deal in some other bargain, in exchange for ownership/control of the indivisible good (129).

With the abundance of pitfalls involved in interstate bargaining, the question arises: why isn’t war more common in the modern era? Decreasing occurrences of war are the result of multiple factors including repeated international interactions, economic ties, democratization, and the ever-increasing cost of war, but one factor in particular is at the forefront of international peacekeeping: international institutions. These interstate mediators, like the U.N., exist to resolve international disputes by acknowledging that bargains begin and end with credibility and reminding actors that there are more reasons to avoid a war than to start one.

Works Cited:

Frieden, J. A., Lake, D. A. & Schultz, K. A. (2019). World Politics: Interests, Interactions,

Institutions (4th ed.). W. W. Norton & Company.