In the wake of Russian actions in Ukraine in 2014, NATO and the United States enhanced their forward posture with a rotational force designed to deter further Russian adventurism. With the additional US force presence in Europe a new reality for the foreseeable future, some have begun to question the efficiency and efficacy of a rotational presence, preferring instead to return additional US combat forces to a permanent posture in Europe. As USAREUR assesses priorities for the potential return of additional capability to Europe on a permanent basis, initial prioritization should go to the formations that contribute to the foundational capabilities outlined in the Chairman's 2012 Joint Operational Access Concepts and 2014 Army Operating Concept. These documents prioritize the Army's role in providing the foundational capabilities necessary to facilitate follow-on Joint Forces in a mature theater. Headquarters, infrastructure, logistics, and intelligence elements will perform the most important functions in enabling follow-on forces in a mature theater with adequate initial NATO conventional combat capability. To reach this conclusion, this monograph first analyzes conventional deterrence theory. Second, an assessment of the current situation in Europe. Third, an analysis of the relative effectiveness and efficiency of rotational forces vs. permanent forward presence. Finally, a discussion of the role of the Army in the Joint Operational Access Concept. When considered together, these variables suggest a return to competition with Russia in Europe, and the necessity to return US and NATO force postures to deterrence over engagement. However, NATO Strategic Concepts still prioritize engagement, a concept that the North Atlantic Council should evaluate in coming years, against the emerging trends in European security affairs. While the alliance evaluates the strategic concept, the US Army should consider the most immediate priorities, those that return US capabilities to a posture suitable for war fighting and deterrence.

Approved for public release; distribution is unlimited. The opinions and conclusions expressed herein are those of the student author and do not necessarily represent the views of the US Army Command and General Staff College or any other government agency. (References to this study should include the foregoing statement.)