The one scenario for which the United States might reasonably make provision for simultaneous action is a potential Russian attack on NATO member states in Eastern Europe. The reason is twofold. First, unlike any potential US adversary other than China, Russia does have a plausible way by which it could seize and hold the key territory of a US ally even in the face of US resistance. Second, Europe is one of the key regions of the world. The fundamental stake at issue for the United States is denying Russia or any other state hegemony over Europe.
