Europe and NATO are preparing for the possibility of a Russian invasion without U.S. support, as concerns grow over the potential for a conflict with Russia. The rise of Donald Trump and his previous statements about NATO have heightened these concerns. European nations are worried that they may have to face Russian forces alone, as some officials and experts believe that Moscow could rebuild its military and potentially invade a NATO nation within the next five years. This has raised doubts about the readiness of NATO militaries to confront Russia.