International Military Intervention, 1989-2005 (ICPSR 21282)

Version Date: Jan 29, 2008 View help for published

Principal Investigator(s): View help for Principal Investigator(s)
Emizet F. Kisangani, Kansas State University; Jeffrey Pickering, Kansas State University

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This project updates INTERNATIONAL MILITARY INTERVENTION (IMI), 1946-1988 (ICPSR 6035), compiled by Frederic S. Pearson and Robert A. Baumann (1993). This newer study documents 447 intervention events from 1989 to 2005. To ensure consistency across the full 1946-2005 time span, Pearson and Baumann's coding procedures were followed. The data collection thus "documents all cases of military intervention across international boundaries by regular armed forces of independent states" in the international system (Pearson and Baumann, 1993). "Military interventions are defined operationally in this collection as the movement of regular troops or forces (airborne, seaborne, shelling, etc.) of one country inside another, in the context of some political issue or dispute" (Pearson and Baumann, 1993). As with the original IMI (OIMI) collection, the 1989-2005 dataset includes information on actor and target states, as well as starting and ending dates. It also includes a categorical variable describing the direction of the intervention, i.e., whether it was launched in support of the target government, in opposition to the target government, or against some third party actor within the target state's borders. The intensity of the military intervention is captured in ordinal variables that document the scale of the actor's involvement, "ranging from minor engagement such as evacuation, to patrols, act of intimidation, and actual firing, shelling or bombing" (Pearson and Baumann, 1993). Casualties that are a direct result of the military intervention are coded as well. A novel aspect of IMI is the inclusion of a series of variables designed to ascertain the motivations or issues that prompted the actor to intervene, including to take sides in a domestic dispute in the target state, to affect target state policy, to protect a socio-ethnic or minority group, to attack rebels in sanctuaries in the target state, to protect economic or resource interests, to intervene for strategic purposes, to lend humanitarian aid, to acquire territory or to dispute its ownership, and to protect its own military/diplomatic interests. There are three main differences between OIMI and this update. First, the variable, civilian casualties, which complements IMI's information on the casualties suffered by actor and target military personnel has been added. Second, OIMI variables on colonial history, previous intervention, alliance partners, alignment of the target, power size of the intervener, and power size of the target have been deleted. The Web-based resources available today, such as the CIA World Fact Book, make information on the colonial history between actor and target readily available. Statistical programs allow researchers to generate all previous interventions by the actor into the target state. Since competing measures and data collections are used for alliances and state power, it was thought best to allow analysts who use IMI the freedom to choose the variables or dataset that measure the phenomena of their choice. Third, the data collection techniques differ from OIMI. OIMI relied on the scouring of printed news sources such as the New York Times Index, Facts on File, and Keesing's to collect information on international military interventions, whereas the computer-based search engine, Lexis-Nexis Academic, was used as the foundation for the new study's data search. Lexis-Nexis Academic includes print sources as well as news wire reports and many others. After Lexis-Nexis searches were conducted for each year in the update by at least four different investigators, regional sources, the United Nations Web site, and secondary works were consulted.

Kisangani, Emizet F., and Pickering, Jeffrey. International Military Intervention, 1989-2005. [distributor], 2008-01-29.

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National Science Foundation (SES-0518294)

1989 -- 2005
2006-09-20 -- 2007-07-21
  1. (1) Variables were reformatted to match the data. (2) Outliers in var_013, var_014, var_015, and var_026 were recoded per PI instruction.


All verified cases of international military intervention from 1989 to 2005.

All cases of military interventions from 1989 through 2005.

Military intervention by state actor, multinational actor, or international organization across interstate boundaries


2018-02-15 The citation of this study may have changed due to the new version control system that has been implemented. The previous citation was:
  • Kisangani, Emizet F., and Jeffrey Pickering. INTERNATIONAL MILITARY INTERVENTION, 1989-2005. Manhattan, KS: Emizet F. Kisangani and Jeffrey Pickering, Kansas State University [producer], 2007. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2008-01-29.