What term describes the conflict between the US and the Soviet Union from 1945 to 1991?

The term that accurately describes the conflict between the US and the Soviet Union from 1945 to 1991 is the Cold War. This period was characterized by political tension, military rivalry, and ideological competition between the two superpowers, as well as their respective allies. Unlike a "hot war," which involves direct military conflict, the Cold War predominantly featured indirect confrontations, propaganda, and various proxy wars around the globe. The competition was mainly rooted in opposing ideologies: capitalism and democracy versus communism and authoritarianism. This long-lasting standoff included significant events such as the nuclear arms race, the space race, and various conflicts influenced by these competing ideologies.

The other terms presented, such as World War III and Hot War, imply direct military engagement on a global scale, which did not occur in this case. The Vietnam War, while a significant conflict during the Cold War period, was specifically one of the many proxy wars rather than a descriptor for the overarching relationship between the United States and the Soviet Union. Thus, the term Cold War encapsulates the nature of the rivalry accurately and historically.