On June 6, 1944, the U.S. Army undertook continental-scale warfare. This summer will mark the 75th anniversary of D-Day, and U.S. Army Europe (USAREUR) will be committed to commemorating the largest amphibious invasion ever known.

Reflecting on the success of Operations Neptune and Overlord--the massive invasion by Allied naval, air, and land forces--one significant factor of their success was a well-oiled sustainment machine. Under different names and in different capacities throughout the seven decades since then, USAREUR has remained ready to undertake large-scale operations enabled by logistics lessons learned.

Today, USAREUR serves as the logistics hub for moving equipment, supplies, and personnel to positions across Europe to support the possibility of large-scale combat. This is done with the knowledge that a future conflict might resemble World War II more closely than recent operations in Iraq and Afghanistan.

This article outlines some of the challenges of continental-scale warfare and describes how USAREUR stays ready to present combat-credible forces by preparing the theater to deter and, if required, defeat any threat. It argues that the scale and complexity of the challenges in Europe are greater than in any other current U.S. theater. However, through our dynamic exercise program and rotations of continental United States (CONUS)-based forces, the formal practice of setting the theater, and our efforts to enhance relationships with allies and partners, USAREUR presents tested solutions applicable to any logistics challenge imaginable. So, a bit like the sentiment Frank Sinatra crooned about in the song New York, New York, "If I can make it there, I'll make it anywhere," if you understand sustainment in Europe, you can make sustainment a success anywhere.

CONTINENTAL COMPLEXITY

The European continent has been the site of many of the 20th century's most calamitous and significant events. In addition to the 75th anniversary of the beginning of the end of Nazi rule in Europe, this year marks the 30th anniversary of the fall of the Berlin Wall, signifying the end of the Cold War.

It is easy to assume that the situation in Europe is unchanged from World War II, but a combination of changing factors reveals the theater to be a more complex environment today than it was before. These factors include heterogeneous perceptions of threat, a multitude of transnational bodies, growing numbers of allies and partners, enormous distances, and highly varied environments and terrain.

Throughout its history, Europe has never had a cohesive identity, and it would be unwise to think of today's theater as homogeneous. Cold War and D-Day planners had the dubious benefit of a single unifying threat. Now, forces in Europe must plan against multiple state and non-state actors with neither a consensus view of the preeminent threat nor a priority of response.

NATO continues to play a vital role in maintaining collective defense in Europe, but it is not the only supranational body in the region. Figure 1 offers a glimpse of the complexity associated with a few of these bodies.

When the Berlin Wall fell, there were 16 members of NATO. Now there are 29, with two more countries engaged in the accession process. In addition, the alliance has a number of formal partners across the region. This increase in membership has had implications for language, doctrine, interoperability, equipment, and interior lines of communication.

The expansion of NATO has greatly increased the length of interior lines of communication. In the 1970s and 1980s, U.S. Army units had to be prepared to move from their garrison locations to the inter-German border, a distance of about 170 miles. Now, troops may be moving up to 1,400 miles from their home stations in Germany to NATO's northeastern flank on the shores of the Baltic Sea or to its southeastern flank on the Black Sea.

With the distances in Europe come varied climates that range from Mediterranean summers to Scandinavian winters. Military sustainers, planners, and operators also must consider diverse terrains, from mountain ranges, such as the Alps and Carpathian Mountains, to the plains of Germany and Poland, and the rolling hills of the Baltic region, which are densely packed with forests and lakes.

From the types of threats to the varied terrain, all of these complexities contribute to the logistics conundrum left for sustainment professionals to solve. USAREUR's dynamic multinational exercise program and the routine rotation of forces into theater tests solutions to these challenges on a continental scale.

LOGISTICS TEST LABS

One of the most salient lessons from Operation Overlord was that preparing for extended combat operations in Europe requires planning well in advance of the point of crisis. USAREUR uses exercises and rotational deployments to test and refine processes for deployment, which provide lessons for planners preparing for any theater. Simply put, our operational plans demand freedom of movement. We achieve this, in part, by projecting forces through multiple ports, both north and south of the Alps.

USAREUR's sustainers use multi-modal movements to ensure there is no single point of failure in the reception, staging, onward movement, and integration of troops and equipment. A 2017 Army Sustainment article described how the command has used brigade combat team rotations from CONUS to test and validate processes. From their arrival at multiple ports, in places such as Zeebrugge and Antwerp, Belgium, brigades have demonstrated their ability to achieve readiness standards at their deployed destinations.

By testing the ability to flow through multiple points of entry, USAREUR develops two capabilities: the ability to open another point of entry if the operational situation demands it and the necessary infrastructure to support a variety of potential operations. The use of multiple locations strengthens host-nation partnerships and builds familiarity working alongside commercial partners.

In Europe, National Guard and Army Reserve rotational units provide a unique capability that highlights the total Army construct and offers planners in other theaters an off-the-shelf catalyst for sustainment success. Since most sustainment capabilities are in these two components, they become key enablers.

The 191st Combat Sustainment Support Battalion (CSSB), an Army Reserve unit, is currently providing sustainment support to rotational units stationed and training in Poland, the Baltic States, and Scandinavia. The 191st CSSB supports and trains under the direction of the 16th Sustainment Brigade. This training allows the CSSB to receive real resupply missions with real deadlines.

Deploying units like the 191st CSSB strengthens USAREUR's readiness. They provide the command with additional combat sustainment support capacity that complements permanently stationed units. Their rotations also further the reach of lessons learned from encountering the logistics complexity of the European theater.

The USAREUR exercise program has assigned and rotational forces training alongside our allies and partners more than 50 times a year. This year's focus exercises will happen in the Black Sea region with Saber Guardian. Last year, we deployed units across the Baltics and Poland with Saber Strike. These exercises build our sustainment relationships with allied and partner armed forces and help to identify and solve multinational logistics challenges now so they do not become vulnerabilities later.

In the future, USAREUR will use Exercise Defender 2020 to gather further lessons. Defender 2020 is a Department of the Army-directed, USAREUR-led exercise designed to demonstrate the United States' ability to rapidly deploy a division to the European theater. This exercise, the largest in 25 years, will test echelons-above-brigade units in operational-level warfighting and its associated sustainment.

Through our rotations of combat and sustainment forces as well as through our exercise program, USAREUR, along with its allies and partners, maintains readiness by adapting to today's lessons learned rather than waiting until a crisis emerges. These missions allow us to test the capabilities of air and sea ports, which leads to improved processes, infrastructure, capabilities, and contracts.

The strength of these relationships sustains our ability to rapidly project combat forces to the point of need. Without this flexibility, USAREUR's ability to achieve an advantageous accumulation of forces and supplies would be degraded.

Command Sgt. Maj. Rocky L. Carr, 21st Theater Sustainment Command (TSC), summed it in the following way: This theater is a laboratory for sustainment training, and each unit that gets the opportunity to train here leaves better.

SETTING THE THEATER

Another way USAREUR creates the strategic advantage is by setting the theater in anticipation of crises and contingencies by staging pre-positioned stocks and practicing military mobility.

During the Cold War, Europe was arguably the best-set theater ever. Hundreds of thousands of assigned forces were stationed in Germany and the annual Return of Forces to Germany (REFORGER) exercise practiced NATO's ability to reinforce its presence rapidly. The exercise peaked in 1988, when 125,000 troops deployed. This required significant enabling capabilities, with the creation and maintenance of pre-positioned stocks, air movement staff, fuel pipelines, and so forth.

With the decrease of U.S. personnel in Europe, the Army's ability to maintain such a well-set theater reduced commensurately. Nevertheless, the 21st TSC must still be able to open the theater to allow for the inflow of troops from CONUS. To this end, many of USAREUR's permanently assigned personnel are enablers. They sustain the troops already present in Europe, enable theater opening, and protect Army personnel, materiel, and installations in theater.

For logisticians in Europe, this has had a number of key implications, including growing Army pre-positioned stocks (APS), developing a variety of port operations options across the continent, liaising with rail network operators, and improving convoy operations.

As the Army continues its focus on setting the European theater, APS has become an important part of strategic mobility, readiness, and deterrence. By positioning equipment and supplies forward in combat-configured sets, the time needed to respond with capable forces from CONUS is reduced significantly. Since 2017, the number of APS locations has increased from one to four. Alongside equipment sets for three combat formations and a division headquarters, there are also equipment sets to enable the movement and sustainment of these forces.

Growth of equipment sets will continue through 2021. USAREUR has also established the European Enduring Equipment Set. Units training in Europe can draw equipment from this set, reducing the cost of deploying equipment from CONUS.

ENHANCING RELATIONSHIPS

Another variable that adds to the complexity of movement in Europe is that national diplomatic clearance standards vary by nation. The work of USAREUR with national movement coordination centres, host nations, and the 21st TSC's Theater Movement Control Element has streamlined the ability to complete requisite travel documentation to cross borders safely and responsibly.

Re-establishing road movements across Germany and Poland allows our forces to learn post-Cold War lessons, while working with host nations to ensure freedom of movement. In addition to routine movements in support of exercises, our sustainers conduct route reconnaissance to determine the capabilities of roadways in Europe.

These efforts require collaboration among military police, engineer, transportation, and civil affairs units as well as host nations. The result is a holistic view of roadway capabilities; measures to mitigate capability shortfalls and work with host nations to potentially upgrade infrastructure are identified.

For these reasons, it is critical for sustainment professionals and planners to prioritize establishing and strengthening relationships with allies and partners.

During the planning for the D-Day invasion, Allied forces had to solve logistics problems upon which the fate of the world hinged. If the United States is to ever again engage in continental-scale warfare, it will almost certainly be alongside allies. Therefore, it is critical for USAREUR to build relationships and interoperability with its allies and partners in the region, especially those within the sustainment discipline.

At its simplest level, this is about low-level interactions between junior-enlisted personnel from different armies. Whether support to ceremonial events, the annual Nijmegen marches in the Netherlands, or earning the German armed forces proficiency badge or Italian parachutist wings, such events are typically fun, build relationships, and result in great stories to tell family and friends.

The Conference of European Armies for Noncommissioned Officers event is an example of higher-level work on interoperability. This is an annual opportunity for senior-enlisted leaders from European armies to build relationships, understand capabilities, and ensure continuity of efforts for noncommissioned officer development among allies and partners. All of these events address the human element of interoperability from which development of technical and procedural interoperability can flow.

As mentioned earlier, our joint, multinational exercise program is arguably the most closely integrated, complex, and demanding series of exercises in today's Army. In 2018, approximately 29,000 U.S. personnel participated in 52 exercises, involving more than 68,000 participants from 45 countries. During multinational exercises, our sustainers gain real-time, real-world experience in a partnered European environment. Few other training opportunities involve allies and partners on this scale. The value of the multinational cooperation and lengthy lines of communication make training in this theater invaluable.

With no offense intended to our colleagues at CONUS-based combat training centers, they cannot mimic the language, culture, terrain, distance, and interoperability challenges that units routinely face in Europe. Therefore, they also cannot provide better opportunities for units to adapt to the sustainment challenges encountered here, such as cross-border customs processes or road and training restrictions within and around population centers. Such challenges are more readily overcome by strengthening relationships with allies and partners.

The European theater is different from any other because of its scale, complexity, and the number of allies, partners, and supranational bodies with a stake in the theater. It is tempting to treat contemporary threats and contingencies as though they might merely be reruns of the Cold War, but doing so oversimplifies the changes that have affected the region since the fall of the Berlin Wall.

This theater represents today's most challenging mission set for echelons-above-brigade personnel. USAREUR is required to maintain a combat-credible posture in theater to deter aggression and to be able to conduct large-scale combat operations with allies and partners to maintain collective security in the region.

One way the command does this is by setting the theater. The command's day-to-day business practices develop this line of effort through the rotation of units in support of efforts such as Atlantic Resolve and through a demanding series of national and multinational exercises.

For sustainment professionals, it is difficult to think of a more complex theater than Europe. For leaders at the unit level, consider the challenges of European operations in your professional development activities, while planning exercise, training scenarios, and the integration of National Guard and Army Reserve personnel into your formations.

For leaders involved in developing sustainment doctrine and concepts, think about the scale and complexity of continental warfare in a regionally diverse and densely populated theater. For acquisition specialists, we encourage you to ensure interoperability by design by thinking about how platforms might be used in Europe. By understanding the challenges of the Army's most diverse and complex theater, leaders and sustainment professionals will be better equipped to adapt to any theater in the future.

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Lt. Col. Edward A. Fraser is a British Army infantry officer assigned to the Commander's Initiatives Group, USAREUR, as an exchange officer.

Command Sgt. Maj. Robert V. Abernethy is the senior enlisted leader for USAREUR. He previously served as the senior enlisted leader for the U.S. Army Special Operations Command, at Fort Bragg, North Carolina.
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This article was published in the April-June 2019 issue of Army Sustainment.