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Research Brief

Key Points

  • Most of the Army's active-duty soldiers have deployed, many for the second or third time.
  • To meet demand, the Army has sped up troop rotations to make more soldiers available.
  • The Army retains very limited capacity to deploy additional active-duty soldiers.

In October 2008, the Vice Chief of Staff of the U.S. Army asked RAND Arroyo Center to assess the demands placed upon the Army by deployments to Operation Enduring Freedom (OEF) in Afghanistan and Operation Iraqi Freedom (OIF) in Iraq. This request coincided with some public statements concerning the Army's capacity to deploy additional soldiers to OEF and OIF.

To give the Army and other policymakers a fresh look at Army deployments, RAND analyzed data from the Department of Defense's (DoD) Defense Manpower Data Center (DMDC), which tracks personnel involved in contingency operations. Arroyo's analysis addressed three broad issues: the number of soldiers who have deployed to date; the ratio of soldiers' deployed time to nondeployed time; and the number of soldiers who have not yet deployed and the reasons they have not.

Most Active-Duty Soldiers Have Deployed at Least Once

As of December 2008, the Army has provided over 1 million troop-years to OIF and OEF. Active-duty soldiers alone have contributed over 700,000 troop-years to these two wars. From September 2005 through December 2008, the Army had an average of 128,000 soldiers deployed to OIF and OEF.

Although the Army represented 40 percent of the DoD's active-duty strength in 2008, it provided 52 percent of the forces in Iraq and Afghanistan. Active-duty strength equals the sum of active component end strength, and those reserve component soldiers on full-time active-duty status—as distinct from mobilized reservists. Thus, the Army is sending a much higher proportion of its active-duty soldiers to the ongoing wars than the other services.

To accumulate this much deployed time, most active-duty soldiers in the Army (67 percent) have deployed—and most now deployed are on their second or third tour. Multiple tours have created an increasingly experienced force in OEF/OIF. The figure reflects the cumulative deployments for each service as of December 2008. The numbers around the outside circle (proceeding in a clockwise direction) depict cumulative months deployed, and the rings (moving outward in a radial direction) depict the number of service members who have been deployed for that period of time. For example, 27,000 soldiers had a cumulative deployment time of 13 months; 35,000 had accumulated 15 months.

A Significant Number of Soldiers Are Entering Their Third Year of Cumulative Deployed Time in OIF and OEF

As of December 2008, approximately 373,000 soldiers in the Army had served in OIF or OEF; 173,000 soldiers are working on their second year of deployed time and 79,000 are working on their third year or longer. Of this last group, over 9,000 are deploying for their fourth year.

The Army Has Sped Up Troop Rotations to Make More Active-Duty Soldiers Available

The demand for active-duty soldiers in OEF and OIF would have exceeded supply under the Army's normal deployment policies, so the Army acted to increase supply: it increased the overall size of the active component; reassigned soldiers from other missions to the pool of soldiers rotating to OEF and OIF; and increased the rate at which soldiers rotate to and from the wars.

The DoD measures the rate at which soldiers deploy using a "BOG: Dwell ratio." A 1:1 BOG:Dwell ratio indicates that a soldier spends one time period (typically a year, and sometimes up to 15 months) in theater ("BOG" or "boots on ground"), and the same amount of time not in theater ("Dwell") before returning to theater. A 1:2 ratio indicates two time periods away from theater for every time period in theater, and a 1:3 ratio yields three time periods away from theater for every time period in theater. The DoD goal for the active component is a BOG:Dwell ratio of 1:2.

To maintain the number of soldiers needed in theater, the Army has deployed soldiers at BOG:Dwell ratios between 1:1 and 1:2, and closer to 1:1, for much of the period from 2003 to 2008. The BOG:Dwell ratios the Army has sustained in OIF and OEF show that soldiers have deployed more often than the DoD goal of 1:2 for the active component. However, until recently, demand has increased as quickly as the number of available soldiers, so that there was no net easing of the deployment ratio.

The Army Retains Very Limited Capacity to Deploy Additional Soldiers

Despite the increased rate at which soldiers deploy, the Army retains very limited capacity to deploy additional soldiers to OIF and OEF. As of December 2008, 184,000 out of 557,000 active-duty soldiers had not yet deployed:

  • The majority of these, 109,000, are new soldiers; roughly another 4,000 are cadets at the U.S. Military Academy.
  • Over 10,000 are soldiers forward-stationed in Korea, Europe, or other overseas locations who have not yet served in OIF or OEF.
  • Another 27,000 are in military occupational specialties that support the current war efforts or other contingency missions (e.g., in medical or intelligence related positions), but are not located within Iraq or Afghanistan.
  • Of the remaining 34,000 soldiers, about 3,000 have been injured prior to deployment and are in warrior transition units.

This leaves approximately 31,000 soldiers (about 5.6 per-cent of the active-duty force) who are possibly available for deployment.

In summary, this analysis suggests that the active-duty Army is almost completely utilized (about 94 percent) and retains very little unutilized capacity to deploy additional active-duty soldiers. Virtually all of the Army's currently serving soldiers have either already deployed to OIF/OEF at least once (67 percent) or simply have not served long enough to get deployed (20 percent). The remaining 13 percent is made up of soldiers who in most cases simply have not had an opportunity to deploy to OIF/OEF because they have been needed elsewhere, or who have been injured before having the chance to deploy. Less than 6 percent of active-duty soldiers are potentially available for deployment.

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