War may not be on the rocks, but it is frequently over rocks. Land, to be exact. From the recent war between Azerbaijan and Armenia, to concerns that Russia is preparing to launch an invasion to conquer Eastern Ukraine, war is frequently, if not always, over land.
The international relations scholarship exploring war offers numerous explanations for its occurrence: it’s a “tragedy” brought about by the very nature of the international system; it’s partly how states are formed; or it’s the very thing that gives states meaning. But a key factor, perhaps the key factor, is territory. Indeed, recognizing the centrality of territory in interstate war goes a long way toward explaining why war, though frequently euphemized with phrases like “use of force” or “militarized disputes,” entails using physical violence to cause death and serious injury.
While “territory” can include rivers and waterways, the Issue Correlates of War project run by Sara Mitchell and Paul Hensel finds that the vast majority of territorial disputes in their data concern land. In a recent review of the empirical work on the topic, Paul Hensel and Hein Goemans report that 85 percent of fatal militarized conflicts between states since 1945 involved a territorial issue. Such data reinforces Monica Duffy Toft’s 2014 analysis: “What is clear is that territory has been and will continue to be a core issue in explaining the escalation and onset of war.” This echoed Paul Huth, who wrote nearly 20 years earlier that “one of the enduring features of international politics” is clashes over disputed territory.
Of course, this is not the only type of dispute that states can have. States can become embroiled in disagreements over policy issues, such as the pursuit of nuclear weapons. They can also become involved in disputes over regime type, which is a primary driver of foreign imposed regime change, or over “identity” and the treatment of various ethnic groups, which can provoke internal conflicts and genocides. But time and again, scholarship has found that territorial disputes are most likely to escalate to violent conflict.
What is it about land? Is it simply because land is valuable and disputes over its ownership — like that of any scarce resource — will inevitably lead to fighting? This would be consistent with the hard fact that most of the planet’s surface is comprised of water, not land. But the scarcity of land is only part of the answer.
Political geographers emphasize that the idea of territory should not be conflated with just land. The meaning needs to be considered more deeply. Political actors, such as states, define their ownership of a place as a means of asserting influence. Hence, it is the need to assert influence over others, not the land itself, that drives conflict
Put simply, territory is still largely associated with physical land, and possessing land requires physical presence. Physical action is needed to control a resident population or move someone from that space. Such physical action will be violent when the population does not want to be controlled or the actor holding the land is unwilling to move. Admittedly, states usually prefer to avoid violence. Violence is still costly. Carl von Clausewitz famously quipped that aggressors are always “a lover of peace” — they would like to invade peacefully unless there is organized resistance. This lies at the heart of faits accomplis, an increasingly common means by which states take territory from one another. With a fait accompli, or land grab, a state’s military forces quickly advance and then hold a small slice of territory, usually without shots being fired. A famous example of such an action is the “little green men” used by Russia to acquire Crimea in 2014. The goal is to move quickly and set the status quo for any future fight over the territory. Indeed, the act of embedding troops and militarizing the territory to hold the land is a key reason why such disputes become protracted.
Similarly, states have accomplished “peaceful” territorial grabs by constructing walls. Though territorial defense and acquisition are not the primary reasons states build such walls, this does occur. While a state might build the wall for the purpose of stopping illegal immigration, the wall could be constructed in a manner that it enters the territory under dispute. This is what Israel has done with its border wall that enters the Palestinian territories.
If possible, states will avoid militarization all together in order to acquire disputed territory. Though former President Donald Trump was widely lampooned for suggesting that the United States buy Greenland from Denmark, the truth is that land purchases were not uncommon for much of history. The Louisiana Purchase and the acquisition of Alaska are just two examples familiar to most Americans. Land purchases by states are still done today, though the practice is less frequent and the tracts of land are much smaller.
But make no mistake: While there is a preference to take the land without resorting to violence, that is often not the case. So long as states define themselves according to the territory they hold, peaceful territorial acquisitions will be a novelty in international politics. Even if the territorial nation-state is no longer the primary political unit used to organize human society, land remains relatively scarce. Physical space will be required. While states ceased speaking of “living space” in the same explicit terms as the Nazi regime, the reality is that possessing and holding land will remain valuable.
Some have argued that a post-1945 norm against forceful territorial revisions has reduced the onset of conquest. It is indeed the case that full-on invasion and conquest of another nation is less accepted than in the past, and the practice has become rare. But territorial conflict has not fully disappeared, or even declined. Moreover, some states, particularly those dependent on resource extraction, still find the acquisition of territory by force to be economically profitable.
In fact, the potential flashpoints for a major power war this century all revolve around territory. While Russia’s actions vis-à-vis Ukraine opened this piece, this is just one of several areas, from islands near Japan to water passages in the Arctic, that could emerge as locales of a future territorial-based conflict between Russia and other powers. One must also note the strong territorial element in the disputes between China and its neighbors: fights over the Line of Actual Control with India, disputed claims over islands between China and Japan, and concerns over a potential invasion of Taiwan.
All of this suggests that the future will largely resemble the past: Territory will remain valuable, states will seek to acquire it, and conflicts will inevitably arise. The consequence is that war, particularly over land, is here to stay.
Paul Poast is associate professor of political science at the University of Chicago and nonresident fellow of foreign policy and public opinion at the Chicago Council on Global Affairs. His most recent book is Arguing About Alliances: The Art of Agreement in Military-Pact Negotiations (Cornell University Press). He tweets @ProfPaulPoast.