In 2018, U.S. Army Materiel Command (AMC) described the strategic support area (SSA) and operational support area (OSA) in relation to the Army’s multi-domain operations (MDO) concept. The American homeland serves as the primary SSA for Army units; it is the Army’s initial industrial, supply, manpower, and power-projection base for all operations.Forward-stationed units in Europe, Africa, Asia, South America, and the Pacific function as both a secondary SSA for each theater and an OSA for theater-wide operations. Defining which activities take place in the SSA and OSA provides sustainment commanders, of forces based both in the continental U.S. (CONUS) and forward stationed outside the continental U.S. (OCONUS), a framework to visualize the Army’s sustainment enterprise and their unit’s role in it.Framing the Strategic and Operational Support AreasThe SSA encompasses seven domains: supply availability, industrial base readiness, munitions readiness, Soldier and Family readiness, strategic power projection, installation readiness, and logistics information readiness. According to U.S. Army Training and Doctrine Command (TRADOC) Pamphlet 525-3-1, The U.S. Army in Multi-Domain Operations 2028, the SSA is the “area of cross-combatant command coordination, strategic sea and air lines of communications, and the homeland. Most friendly infrastructure are controlled and located in the strategic support area,” where logistics functions required to support MDO take place. The SSA is largely CONUS-based, but does include forward-stationed installations and sustainment assets such as Army prepositioned stocks (APS). These strategic assets are operationalized in the OSA where units work to achieve and retain superiority.Key sustainment functions occur in the OSA in order to (IOT) enable friendly operations across the area, that often encompass many nations. Due to the nature of the OSA, according to the TRADOC Pamphlet 525-3-1, units are “never out of contact,” because it is “an important space for friendly political-military integration.” CONUS-based units may see little overlap between the SSA and OSA, whereas forward-stationed units navigate the often nebulous border between the two, daily.21st Theater Sustainment Command’s Role in the SSA and OSAAs the Army’s logistics and sustainment force forward stationed in Europe, 21st Theater Sustainment Command (21st TSC) sustains the U.S. Army Europe (USAREUR) commander’s OSA while simultaneously providing SSA functions for multiple theaters: U.S. Central Command (CENTCOM), U.S. Africa Command (AFRICOM), and U.S. European Command (EUCOM). This mission set is unique to 21st TSC. The sustainment problem sets across these regions are particularly complex due to geographic and regulatory dichotomies, time and distance removal from logistics operations in the homeland, the unique nature of military and political relationships throughout each region, and concurrent demand on limited capacity assets. 21st TSC operates in this demanding climate with particular consideration to four of the seven SSA domains IOT advance national strategic goals in each supported SSA and sustain operational overmatch in the European OSA. These domains are strategic power projection, logistics information readiness, supply availability and equipment readiness, and installation readiness.Strategic Power ProjectionArmy strategic power projection (SPP) assets exist to rapidly deploy forces and equipment to meet the needs of combatant commands (CCMD). SPP assets in Europe include American and host-nation (HN) installations and infrastructure of rail terminals, airports, seaports, barge and littoral vessels, and warehouse facilities. Each operates under different regulations and at varied capabilities. Projecting power through and across Europe requires a nuanced understanding of international laws, treaties, border restrictions, multinational agreements, and diplomatic tensions.These tasks lie firmly within the OSA portfolio but are critical to enable cross-border military mobility, the crucial SSA ability to project military assets across national borders throughout Europe and to other theaters in both permissive and contested environments.Acting as a secondary SSA for CENTCOM since 2003, 21st TSC exercised SPP when it deployed U.S. Army Fifth Corps (V Corps), 1st Armored Division, 1st Infantry Division, and multiple other echelon above division (EAD) units totaling thousands of Soldiers and pieces of equipment to operate throughout CENTCOM. Europe’s installation and power projection nodes delivered critical combat power in support of (ISO) Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), Operation New Dawn (OND), and Operation Freedom’s Sentinel (OFS). As recently as April, 21st TSC assets acted as power projection platforms to distribute critical supplies from APS-2, Dulmen Work Site, Germany and other sources in support of CENTCOM’s COVID-19 pandemic mitigation and response operations.Serving this role for AFRICOM, 21st TSC regularly projects forces and equipment into the AFRICOM area of operations (AOR) ISO missions ranging from Ebola crisis management (2015) to ongoing Special Operations Forces (SOF), civil affairs, and training team support missions. The preponderance of service members and supplies routed to Africa originate in or transit through Europe, making this theater a critical secondary SSA for AFRICOM.The delineation of 21st TSC’s SPP as part of the European secondary SSA ISO OSA operations in other theaters is clear. However, when exercising SPP to support operations in the European OSA, this line blurs and 21st TSC often operates at both the strategic and operational levels via complimentary or nested efforts, as seen during preparations for exercise DEFENDER-Europe 20. From 2019 through March 2020, 21st TSC exercised the SPP inherent in APS by having drawn key equipment from APS and deploying it across borders via multiple nodes ISO DEFENDER-Europe 20 objectives. 21st TSC drew and moved 9,000 vehicles and other pieces of equipment from APS for use across Germany, Poland, Belgium, and other DEFENDER-Europe 20 partner nations; thereby having exercised roles as both a secondary SSA and primary OSA for SPP throughout Europe. SSA power projection and OSA maneuver ISO friendly objectives bled inexorably into one another and this tight interrelationship of the European SSA and OSA increases the precision with which it must be navigated.Logistics Information ReadinessLogistics information readiness in the SSA consists of “a variety of information including equipment numbers, what is ready to go, what is coming inbound in the next 24 hours, the number of ships and what's on them, the arrival of Soldiers, highway capacity, the best times of day to drive, and more. That information provides a solid foundation for strategic decision making.” In 21st TSC’s sustainment role for the European SSA, support operations planners require timely logistics information from U.S. forces operating in the EUCOM, AFRICOM, and CENTCOM AORs in order to influence demand signals for supplies and equipment from APS, the CONUS supply base, or local vendors. However, multiple logistics information systems with duplicative inputs and non-aggregated outputs create barriers to anticipation and responsiveness. This hinders implementation of the principles of sustainment and improperly skews toward improvisation as a regular tactic when the systems should be vertically integrated to increase simplicity, economy, and survivability.This SSA capability gap for logistics information readiness exacerbates frictions in OSA activities for these three CCMDs due to significant language and systems communications lapses between the U.S., allies, and partner nations. Support operations planners at 21st TSC require input from across the dozens of nations in the USAREUR OSA and the aggregation of demand from CENTCOM and AFRICOM to properly maintain supply availability, equipment readiness, and achieve power projection across and outside of Europe. However, there is no single (or even few) approved system(s) to consolidate and achieve a common logistics operating picture for multinational operations.This issue is continually voiced as an impediment to success by participants in Europe’s multinational exercises, to include DEFENDER-Europe 20. Due to security concerns, each partner nation retains its own internal communication systems which are incompatible with other nations’ technologies. Access to NATO Secret terminals is very limited, even among American forces. A recent push to develop the Mission Partner Environment (MPE) network produced promising results during planning for DEFENDER-Europe 20. While the technology requires further development and wider distribution, 21st TSC took the first step toward a paradigm shift from purely-U.S. systems to one that is usable by many nations’ forces. The lack of interoperability between NATO, allied, and partner nations considerably slows commanders’ visualization of the logistics common operating picture and significantly hinders the ability of the alliance to react quickly during a time of crisis. This capability gap between the logistics information systems development and European OSA requirements has resonant consequences for sustaining a multinational force in the event of a European conflict. Each added layer of complexity increases the chances of sustainment being late to need.21st TSC overcomes this challenge by implementing internally created and maintained tracking systems to account for demands by theater, type, time horizon, recurrence, and frequency of need. The responsibility to provide logistics information readiness for American and supported allies’ demand to SSA assets in three CCMD AORs is unique to 21st TSC.Supply Availability and Equipment ReadinessThe industrial base and resupply capabilities enjoyed by CONUS-based units are delayed and often degraded OCONUS. During the lag time between need and fulfillment, OCONUS unit commanders assume a level and type of risk that their CONUS counterparts do not encounter. This is further exacerbated by Europe’s role as a secondary SSA for CENTCOM and AFRICOM, thereby increasing the demand on both supplies and distribution systems. In alignment with the 2018 National Defense Strategy mandate to prioritize prepositioned forward stocks and munitions, and strategic mobility assets, the Department of Defense and Department of the Army bolstered APS, ammunition depots, and supply stockpiles throughout Europe. Even these extensive assets do not entirely bridge the gap.For example, Class V (ammunition) stockpiles in Europe are part of both EUCOM and AFRICOM SSA supply assets. 21st TSC retains responsibility to orchestrate the call forward, realignment, and retrograde for all ammunition shipments to and from Army Depot Miesau. This task encompasses SSA functions of logistics information readiness for reporting through multiple systems, installation readiness for the depot itself, and the projection of required Class V to the theater. To achieve this end state, 21st TSC navigates the OSA’s political-military environment, movement restrictions and agreements, and cross-border military movement procedures.APS are also critical to supply availability and equipment readiness. These stocks, maintained by AMC, are an extension of the SSA embedded in the OSA. They are utilized for large-scale combat operations, small-scale contingencies, national emergencies, peacetime emergencies, or exercise support. APS-2 and APS-7, equipment sets for EUCOM and AFRICOM respectively, are both located in Europe and under the operational control of 21st TSC, with the responsibility to maintain availability and readiness and to forward deploy those assets in line with CCMD requirements. This straddles the SSA–OSA divide for multiple areas of responsibility.Installation ReadinessInstallation readiness requires a focus on facilities and infrastructure that keeps the Army deployable to include everything from on-post housing to airfields, railheads, and motor pools. The unique nature of Europe as both the USAREUR OSA—and a SSA for CENTCOM, AFRICOM, and EUCOM—coupled with the aforementioned power projection and communications challenges, increases the importance of installation readiness for 21st TSC and supported units.The 21st TSC commander’s roles as senior responsible officer (SRO) for installations and garrisons across the Rheinland-Pfalz region and the deputy commanding general, sustainment, for all of USAREUR confer particular onus upon him or her to ensure that all infrastructure is prepared to project power within and outside of Europe. Within the SSA context, this includes maintenance of strategic sea and air lines of communication such as ports, open waterways for barging and littoral operations, depots, warehouses, Army airfields, rail heads, and so on to enable SPP for the EUCOM commander or ISO CENTCOM and AFRICOM operations, like the Ebola response or COVID-19 patient reception, as well as planned training exercises and deployments.This strategic role is complimented by the OSA activities executed by both 21st TSC’s assigned units and the SRO area garrisons. OSA activities, ranging from housing quality-of-life issues or commissary stocks to strategic placement of unit growth across the continent, are informed and influenced by the strategic requirements 21st TSC faces to support operations across EUCOM, CENTCOM, and AFRICOM as well as the political environment of Europe.21st TSC’s ability to execute both SSA and OSA responsibilities for installation readiness was tested during the height of COVID-19 pandemic mitigation and response operations in March/April. Focus quickly shifted from DEFENDER-Europe 20 to the safety of personnel and the movement of Class VIII medical supplies and personal protective equipment (PPE) via ground and air platforms on our installations.Garrisons within the 21st TSC SRO’s area converted buildings into medical treatment and isolation facilities. Transportation assets launched from a bevy of installations to distribute medical equipment, PPE, medical teams, and enhanced testing capabilities to protect American, allied, and host nation lives in CENTCOM, AFRICOM, and EUCOM. This level of response demonstrates again how tightly linked SSA and OSA activities are for 21st TSC.Summary and Conclusion21st TSC, the Army’s theater sustainment command in Europe, faces singular realities to provide SSA to three CCMDs and simultaneously provide OSA functions in a complex, ever-changing environment. The complexities of navigating this unique mission set stretch the 21st TSC’s capacity particularly across the domains of SPP, logistics information readiness, supply availability and equipment readiness, and installation readiness where SSA and OSA responsibilities inexorably intertwine.--------------------Maj. Catherine “Cait” Smith currently serves as force management officer (FA-50) for 21st Theater Sustainment Command, Kaiserslautern, Germany. A native of San Antonio, Smith received the MacArthur Leadership Award in 2016. She earned a Master of Business Administration as a graduate of the Major General James Wright Fellowship, and she participated in the British Ministry of Defence Joint Service Command and Staff College.Maj. Robert McDonough currently serves as chief, Commander's Initiative Group, for 21st Theater Sustainment Command. A native of Kennett Square, Pennsylvania, McDonough has been awarded the Distinguished Flying Cross and the Bundeswehr Cross of Honour for Outstanding Deeds.Capt. Joe Friedman currently serves as the operations officer (S3), 405th Army Field Support Brigade, Kaiserslautern, Germany. A native of Warminster, Pennsylvania, Friedman previously served as commander, Juliet Company, Field Support Company, 1st Battalion, 26th Infantry Regiment, at Fort Campbell, Kentucky. He is a graduate of The Sabalauski Air Assault School.John Gallagher is a Supervisory Traffic Management Specialist with the Theater Movements Center, 21st Theater Sustainment Command, Kaiserslautern, Germany. A 1993 graduate of University of Massachusetts at Amherst, he has served in the Army Transportation Corps in military and civilian capacities since June 1993, including Battalion Command of 838th Transportation Battalion, 598th Transportation Brigade (Military Surface Deployment and Distribution Command).--------------------This article was published in the July-September 2020 issue of Army Sustainment.RELATED LINKSArmy Sustainment homepageThe Current issue of Army Sustainment in pdf formatCurrent Army Sustainment Online ArticlesConnect with Army Sustainment on LinkedInConnect with Army Sustainment on Facebook