troopdata: Tools for Analyzing Cross-National Military Deployment and Basing Data

The goal of the {troopdata} package is to facilitate the distribution of military deployment and basing data for use in social science research and journalism. The troop deployment data were initially compiled by Tim Kane using information obtained from the U.S. Department of Defense’s Defense Manpower Data Center (DMDC). The original data ended in 2005 and we have updated it to run through March 2026.

Similarly, the basing data were initially compiled by David Vine, and we have updated the original data using open source information from the U.S. military and press reports through 2018. We have also assembled this R package to allow users to more easily access the data and use it in their own research.

The package will be updated with additional features in the future, but for now please let me know if you find any errors.

Please refer to the bottom of this page for citation information.

You can also find more information on the package and changes corresponding to each update here: https://meflynn.github.io/troopdata/index.html

Installation

You can install the troopdata package from CRAN or GitHub with:

#install.packages("devtools")

install.packages("troopdata")

or 

devtools::install_github("meflynn/troopdata")

Use

This package currently has four functions:

get_troopdata(): Returns a data frame containing U.S. military deployment values. Depending on the arguments specified the function returns total troop deployments, or total deployments plus service branch-specific deployment values, guard and reserve values, and DoD civilian values. Users can specify select countries and years, or call the entire data frame. Annual values are the highest value reported in a given year. Quarterly values and data for individual US states are also available.

get_basedata(): Returns a data frame containing information on U.S. military bases around the globe from the Cold War forward. Depending on the arguments specified the function will return the entire data set or data for a particular country. Observations can be site-specific or can be aggregated to generate country counts.

get_builddata(): Returns a data frame containing geocoded location-project-year information on U.S. military construction spending, in the United States and overseas. Users can specify select countries and years, or call the entire data frame. The data cover fiscal years 2000 through 2026.

get_exercises(): Returns a long format data frame containing data on military exercises. These data were originally compiled by Vito D’Orazio and Kevin Galambos.

Examples

You can find more detailed vignettes on these functions below:

1. get_troopdata
2. get_basedata
3. get_builddata
4. get_exercises

The Rebuild Notes explain how the troop deployment values are put together, including how annual values are chosen, what zeros and missing values mean, and which values are estimates.

A note on country codes

The original DMDC data contain information on U.S. troop deployments to a wide range of locations, including several non-state territories and subnational units (e.g. Okinawa). The troop deployment and construction data use Gleditsch and Ward country codes as the primary host ID variable. That list has no codes for most territories, so we assign our own. Puerto Rico is 6, Greenland is 1002 and Guam is 1008, for example, which lets users distinguish cases where deployments are present in a territory versus the metropole. Note that these are not Correlates of War (COW) codes. Germany, for example, is 260 rather than 255. The Vine basing data have not been rebuilt yet and still use COW codes, and there some smaller territories have the code of the power that controls them. Using the ISO country codes provides some additional flexibility when calling the data. Worst case, you can pull the full data frame and look around at the specific observations and figure out what best suits your needs.

How to cite this package and data?

When using the updated troop deployment data and/or the troopdata package please cite the following:

• Michael A. Allen, Michael E. Flynn, and Carla Martinez Machain. 2022. “Global U.S. military deployment data: 1950-2020.” Conflict Management and Peace Science. 39(3): 351-370.

Kane’s original troop deployment data collected from 1950-2005:

• Kane, Tim. 2005. “Global U.S. troop deployment, 1950-2003.” Technical Report. Heritage Foundation, Washington, D.C.

Vine’s original basing data:

• Vine, David. 2015. “Base nation: How U.S. military bases abroad harm America and the World.” Metropolitan Books, Washington, D.C.

Construction data

• Michael A. Allen, Michael E. Flynn, and Carla Martinez Machain. 2020. “Outside the wire: US military deployments and public opinion in host states.” American Political Science Review. 114(2): 326-341.

Military exercise data:

• D’Orazio, Vito; Galambos, Kevin, 2021, “Multinational Military Exercises, 1980-2010”, https://doi.org/10.7910/DVN/KHFODX, Harvard Dataverse, V1.