Ever since Russia’s military annexation of Crimea in 2014, the United States military has increased its presence and overall readiness throughout Eastern Europe. However, despite the presence of some 17,000 American troops on the continent, defense officials have repeatedly called for additional support, pointing out that NATO forces throughout the region are too sparse to actually prevent a Russian invasion if ever one were to occur.

It’s with that concern in mind that the U.S. Army recently announced plans to launch the largest U.S. military exercise in Europe in over two decades, set to commence in the Spring of next year. This new drill, dubbed Defender-Europe 20, will see the deployment of 20,000 additional U.S. troops, equipment, and gear to the European theater where they will bolster the 17,000 already present and be joined by military forces from a number of allied nations for a series of drills and war games.

In a very real sense, this deployment can be seen as two massive logistical and strategic litmus tests for the U.S. military. First, the Army has to demonstrate its ability to rapidly move twenty thousand troops along with their equipment thousands of miles over open ocean. While this type of exercise was done in far larger scale throughout the Cold War, with some such drills including over 125,000 troops, it’s been decades since the Army has attempted anything of the sort. This sort of enterprise is about far more than getting the boots on the ground — it’s about getting vehicles, maintenance, supplies, and support gear on station as well.

Once the Army has accomplished that feat, the second significant set of challenges will lie ahead: starting with quickly developing interoperability with allied forces operating different types of equipment and often, speaking different languages. The United States military has devoted a great deal of energy to cultivating interoperability between its forces and allied nations for years, but differences in culture and technology remain an ever-present challenge in the chaos of battle.

(US Army photo by Paul Hughes, 7th Army Training Command, Germany)

This drill won’t just be a test of how well the U.S. Army can rapidly deploy a great deal of power to Russia’s front doorstep, it will also serve as a sort of infrastructure test for Europe as well. Moving a sizeable military force around the continent for what are sure to be months of drills will quickly show whether or not Europe’s roadway infrastructure can support the rapid deployment and redeployment of heavy tracked vehicles and the like. There’s a very real chance American forces may find themselves hindered by geographical limitations in Europe that would need to be identified and addressed before any real conflict were to kick off.

Defender-Europe 20 will be the largest American training revolution in Europe since the heyday of the Cold War, proving once again that the United States has shifted its focus away from counter-insurgency operations and once again toward the idea of high-level near-peer conflicts. It also pales in comparison to recent Russian military drills in the same region, with 2017’s Zapad drills in Belarus seeing more than 40,000 Russian troops participating on the European border, and 2015’s drills of the same name seeing nearly 100,000 Russian troops present.