International Military Deployments Dataset (IMDT), 1962–2022

Abstract

The International Military Deployments Dataset (IMDT) is a dyadic dataset of 21,217 country-country-year observations recording interstate military deployments worldwide between 1962 and 2022. It covers 173 deploying states and 174 host countries and records: troop numbers (disaggregated where possible into combat personnel and military observers); mission types (peacekeeping, counter-insurgency, training, maritime security, air security, contested territory); organisational mandates (UN, NATO, EU, AU, ECOWAS, ECOMOG, ECCAS, NARC, SADC, OSCE, US-led non-NATO coalitions, other regional organisations); operation names; and provenance flags. Countries are coded using the Correlates of War (COW) numerical country code system, making the data directly compatible with ATOP, the COW Alliance Data, the UCDP/PRIO Armed Conflict Dataset, the Defense Cooperation Agreements Dataset, the SIPRI Arms Transfers Database, and other established quantitative IR resources. Source attribution. The primary empirical source is the International Institute for Strategic Studies (IISS) Military Balance annual publications, supplemented by the United Nations Department of Peace Operations peacekeeping databases, NATO and Canadian Department of National Defence web archives, Allen, Flynn and Martinez Machain (2022) for US deployment cross-validation, and Vignoli and Coticchia (2022) for Italian operations. Of the 21,217 observations, 20,747 (97.8%) are coded from Military Balance country entries; 454 are gap-filled from secondary sources; and 16 are constructed by temporal interpolation between anchor years. The IMDT records factual deployment information recoded into a novel dyadic Correlates of War framework. It does not distribute any text, tables, analytical commentary or editorial assessments from The Military Balance; users who need the detail of a source entry should consult the corresponding edition. Users of the IMDT should cite both the IMDT paper (Maltsev, Gatskovskaya and Stasevski, forthcoming, Conflict Management and Peace Science) and The Military Balance (London: International Institute for Strategic Studies, annual) in any work derived from this dataset. Version 2.4 (5 October 2026) removes the free-text field Additional_Info, which contained coders' transcriptions of the Military Balance entries used for coding (an internal audit trail, not used in any analysis). All observations and all other variables are unchanged, and all results in the article are reproduced identically. Version 2.3 should no longer be used or redistributed.