26 May 2023

The Aftermath of a Great Power War

Miranda Priebe, Bryan Frederick, Anika Binnendijk, Alexandra T. Evans, Karl P. Mueller, Cortez A. Cooper III, James Benkowski, Asha Clark, Stephanie Anne Pillion

Wars between states are rare, and great power wars — conflicts that involve two or more of the most powerful states in the international system — are even less common. Still, such wars have historically been among the most consequential international events, as they lead to massive casualties and destruction and have the capacity to reshape societies and the international system.

A review of historical great power wars shows that prewar predictions about who would fight, how long the war would last, and how the world would look afterward were often wrong. This history underlines the need for defense planners to carefully examine their assumptions and to seriously consider both intended and unintended outcomes of great power conflicts.

As the Department of Defense increasingly focuses on competition with Russia and China, RAND Project AIR FORCE (PAF) examined four scenarios illustrating how hypothetical wars with these countries could produce unwanted consequences for the United States — even if the United States is victorious. This report was finalized in January 2021, before the February 2022 Russian invasion of Ukraine. It has not been subsequently updated.

The history of great power conflict is littered with mistaken predictions. An examination of ten great power wars since 1815 found that, in all cases, politicians and military planners held poor assumptions and made inaccurate predictions about critical aspects of the war that would follow (Table 1). Some of those mistakes are described below.

Incorrect predictions about the parties to a conflict and adversaries' will to fight a long war: Great powers have frequently misunderstood other states' interests and therefore failed to predict the likelihood of third-party interventions in a conflict. Noteworthy examples include Adolf Hitler's underestimation of French and British commitments to Poland in 1939 and Kim Il Sung and Joseph Stalin's assumptions that the United States would not fight to defend South Korea in 1950. In other instances, great powers recognized that their actions might provoke another state to get involved but underestimated that state's willingness to sustain a protracted and costly war.

Misunderstanding the effects of new technology: Strategists often overlooked or discounted evidence that a new technology had altered the conduct of war or the distribution of power. Before World War I, for example, European planners misinterpreted or overlooked ample evidence that changes in technology, organization, and the conduct of war (e.g., trench warfare and chemical weapons) would make battles longer, costlier, and less decisive.

Incorrect predictions about the length, intensity, or cost of conflict: Great powers have frequently underestimated the conflict's duration and the scale of military losses. Perhaps the most infamous example is World War I and the European powers' prediction in July 1914 that the conflict would be over by Christmas.

Misunderstandings about the consequences of conflict: States have struggled to foresee the strategic consequences of a conflict, including the durability of wartime gains, the ease of restoring stability, the risk of a conflict recurring, and the long-term implications for the balance of power. Concentration on the task of defeating a rival or securing territorial and political concessions has often led states to overestimate their ability to hold onto wartime gains, as Japan discovered after its wars with China in 1894 and Russia in 1905. Similarly, states have overestimated how decisive a war's outcome would be, or they have underestimated the risk of postwar instability. Territorial compromises and new governing arrangements can produce or inflame new flash points for later crises. For example, having allied to wrest Schleswig-Holstein from Denmark in 1864, Austria and Prussia went to war a mere two years later, partly over control of the same territory. A war's potential effect on the regional or international balance of power can be difficult to predict. For example, neither U.S. nor European strategists anticipated the scale of U.S. military, industrial, economic, and political domination that followed World War II.

Why did politicians and military planners get it so wrong? In some cases, there were obvious shortcomings in analysis or decisionmaking. In other cases, states that historically had been dominant overlooked new evidence, such as the consequences of changing military technology, that the distribution of power had shifted. Even states that avoided known decisionmaking pitfalls faced uncertainty because of a lack of information and the difficulty of predicting the complex interactions that might occur during and following a large-scale war. Regardless of the causes of these incorrect predictions, their legacy reinforces for today's planners and decisionmakers the importance of humility in predicting the course of a conflict or the postwar environment. Leaders and planners should question their own assumptions about the nature of the conflict, its outcome in terms of winners and losers, and the geostrategic aftermath. Examining a range of scenarios with different outcomes can help leaders and planners think about the choices they might face if future conflicts and their aftermaths do not turn out as expected.

Table 1. Accuracy of Key Predictions Prior to Great Power Wars

No comments: