The United States maintains the largest active troop presence abroad of any country in the world, with over 170,000 active duty military personnel stationed overseas as of March 2021. In addition to waging the “Global War on Terror,” the United States has also relied on “force management” and “military operations other than war” to conduct training and security assistance missions, to reassure allies, and to use force short of war to deter adversaries and advance US foreign policy objectives. 2 According to the Department of Defense, global force management is the “processes that align force assignment, apportionment, and allocation methodologies in support of strategic guidance.” Military operations specifically conducted for purposes of coercion were examined by Melanie Sisson, James Siebens, and Barry Blechman of the Stimson Center’s Defense Strategy and Planning program in the edited volume, Military Coercion and US Foreign Policy: The Use of Force Short of War (Routledge 2020). This study included the analysis of an original dataset of more than 100 instances of US military coercion against other countries since 1991. The annual targets of these operations for the years 1991-2018 are represented by the target symbols on each map. The type of operations captured include purposeful shows of force, such as targeted patrols, exercises, and rapid-reaction deployments, as well as limited uses of kinetic force, including missile- and air-strikes, bombings, and peace enforcement missions, etc.
DMDC data is the most complete public accounting of the current location and status of American forces stationed abroad, and thus it is an important resource in evaluating current and historical US military posture. The data demonstrates the global reach of the US military and provides insight into the United States’ post-Cold War priorities and operations. The classification of the number of deployed troops in Afghanistan, Iraq, and Syria from December 2017 onward has only heightened the importance of continued accessibility to this data.
The Center for Data Analysis at the Heritage Foundation previously released a troop deployment dataset for 1950-2005, which has not been updated since its initial publication. For the data for 1991-2005, we cross-referenced the Heritage Center’s collected data with the DMDC’s historical Worldwide Manpower Distribution by Geographical Area reports for the same years. For the years 2008-2018, we pulled the September quarterly reports for each year they were available as a snapshot for the number of troops deployed in a country. Following the December 2017 classification of the U.S. troop presence in Iraq, Syria, and Afghanistan, we relied on the numbers obtained by Just Security for 2018-2020. For the years 2006 and 2007, of which there is no publicly released data from the DMDC, we extrapolated projected troop numbers based on an average between 2005 and 2008. The exception for 2006 and 2007 is Iraq and Afghanistan, for which there is publicly reported “Boots on the Ground” reports. For these two countries, we relied on the September “Boots on the Ground’ reports.
It is important to note that the DMDC reports do not paint a complete picture of where and how many US troops are stationed abroad. The data collected for this study only account for “permanently assigned” active duty personnel, defined as forces deployed for a time period of over ninety days. US reserve forces or active duty forces deployed on a rotational basis, or for operational deployments of less than ninety days, are generally not included in the official figures. The differences between temporary and permanent personnel can be significant. For example, in September 2017, the Department of Defense catalogued the total number of permanent and temporary troops operating in Afghanistan, Iraq, and Syria to be 15,298, 8,892, and 1,720 respectively. But in the DMDC report from December 2017, the total number of permanently assigned troops listed as stationed in all three countries numbered less than 1,000. The DMDC data also does not include Department of Defense contractors, comprising a significant portion of the US presence in Iraq and Afghanistan. Recognizing the limitations of the data in representing the entirety of the US military’s global footprint, the DMDC reports nevertheless remain an important and authoritative resource.
- Tim Kane, Ph.D., Troop Deployment Dataset, 1950–2005, distributed by the Heritage Foundation Center for Data Analysis, https://www.heritage.org/defense/report/global-us-troop-deployment-1950-2005;
- U.S. Department of Defense, Defense Manpower Data Center (DMDC), Military and Civilian Personnel by Service/Agency by State/Country. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports;
- U.S. Department of Defense, Defense Manpower Data Center (DMDC). Worldwide Manpower Distribution by Geographical Area. https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports;
- Joint Staff, Joint Chiefs of Staff, “Summary Table, “Boots on the Ground,” September 2001-November 2008, cited in Congressional Research Service, “Troop Levels in the Afghan and Iraq Wars, FY2001-FY2012: Cost and Other Potential Issues,” Amy Belasco (2009), 61-66. https://fas.org/sgp/crs/natsec/R40682.pdf;
- Sam Aber, Nicole Ng, Phil Spector, and Brandon Willmore, “Just Security Obtains Overseas Troop Counts That the Pentagon Concealed from the Public.” Just Security, March 4, 2021. https://www.justsecurity.org/75124/just-security-obtains-overseas-troop-counts-that-the-pentagon-concealed-from-the-public/