n 2018, the National Defense Strategy formally codified the latest shift in U.S,threat perceptions, heralding Russia as one of the “principal priorities” for the,U.S. Department of Defense. In this Perspective, we illuminate the implications,Iof the United States and its NATO (North Atlantic Treaty Organization) allies,participating in a conventional military confrontation with Russia in Europe and the associated risk of nuclear escalation. This Perspective primarily draws on recently published
