Correlates of War

Correlates of War is a long‑running quantitative research project that compiles systematic historical data on state interactions, conflicts, and capabilities to test theories in International relations theory, Political science, History of warfare, and Peace and Conflict Studies. Founded by scholars associated with J. David Singer and Melvin Small, the project produces datasets used by researchers working on topics from World War I and World War II to the Cold War, Korean War, and Vietnam War. The project’s resources have been applied by analysts at institutions such as Harvard University, Stanford University, Princeton University, University of Chicago, and Yale University.

Overview

The project began in the late 1960s with efforts by scholars at University of Michigan and expanded through collaborations with researchers at University of California, Berkeley, Columbia University, Georgetown University, and London School of Economics. Its core ambition parallels earlier data efforts like the Polity Project and the World Bank datasets but focuses specifically on interstate conflict, territorial changes, and national capabilities. Influential contributors include Bruce Russett, Kenneth Waltz, James Fearon, Paul Diehl, Ted Robert Gurr, and Kenneth Bollen, whose work intersects with debates addressed at venues such as the American Political Science Association and journals like International Organization and Journal of Conflict Resolution.

Data and Methodology

The project compiles multiple datasets, including the Interstate War dataset, the Militant Militarized Interstate Disputes dataset, and the National Material Capabilities dataset. These datasets code events and units of analysis across periods such as the Napoleonic era, the Franco-Prussian War, the Crimean War, World War I, World War II, and post‑1945 crises like the Suez Crisis, the Six-Day War, and the Yom Kippur War. Methodological foundations draw on the work of Karl Deutsch, Harold Lasswell, Samuel Huntington, Robert Jervis, and Alexander Wendt. Coding rules reference primary sources like the Treaty of Versailles, the United Nations Charter, and archival collections at the National Archives and Records Administration, British National Archives, and Bibliothèque nationale de France. The project's techniques have been compared with event‑data schemes from Gleditsch and Ward, the Integrated Crisis Early Warning System, and the Human Rights Data Analysis Group.

Major Findings and Measures

Major measures include state capabilities (aggregate manpower, military expenditures, iron and steel production), alliance patterns, imperial possessions, and territorial change. Empirical findings link power asymmetries to bargaining outcomes discussed by Thomas Schelling, connect regime durability debates involving Juan Linz and Barack Obama (as referenced in comparative work), and inform theories of escalation examined by Mearsheimer and Stephen Walt. Analyses using the datasets address hypotheses about the causes of Great Power wars, the frequency of interstate wars since the Concert of Europe, and the decline of battleship‑era naval engagement as seen in the Battle of Jutland. Correlations between capability distributions and conflict onset have been used alongside models by Bruce Bueno de Mesquita, Doyle, Alexander George, and John Mueller.

Criticisms and Debates

Critics have challenged the project on issues of measurement, selection bias, and definitional choices, echoing debates raised by Theda Skocpol, Tilly, Quincy Wright, and Hans Morgenthau. Scholarly disputes involve comparisons with qualitative case studies by E. H. Carr and John Lewis Gaddis, and methodological critiques from proponents of constructivism such as Nicholas Onuf and Friedrich Kratochwil. Debates have addressed the operationalization of war thresholds, the treatment of civil wars like the Spanish Civil War and Chinese Civil War, and the temporal coverage relative to census records from United States Census Bureau and industrial statistics compiled by Werner Sombart and W. W. Rostow. Methodologists like Gary King and James E. Alt have discussed statistical handling, while historians point to archival revelations from Vladimir Lenin era documents and declassified files from Central Intelligence Agency and KGB collections.

Applications and Influence

The datasets underpin quantitative studies at Massachusetts Institute of Technology, Duke University, Johns Hopkins University, George Washington University, and Cornell University, and inform policy analysis at RAND Corporation, Brookings Institution, Council on Foreign Relations, and the United States Department of Defense. They are used in constructing models for forecasting crises in collaborations with NATO, European Union, and African Union analysts and in curricular materials at West Point, Naval War College, and Air War College. The project's influence extends into work on conflict prevention by practitioners associated with the United Nations Security Council, International Crisis Group, Amnesty International, and Human Rights Watch, and it shapes comparative research featured in edited volumes from Cambridge University Press and Oxford University Press.

Category:International relations