What term describes the period of reduced tensions between the U.S. and its main Communist rivals?

The term that describes the period of reduced tensions between the U.S. and its main Communist rivals is Detente. This era, primarily during the 1970s, was marked by a relaxation of tensions and improved diplomatic relations, especially between the United States and the Soviet Union. It involved several key initiatives, including arms control agreements such as the Strategic Arms Limitation Talks (SALT) and efforts to promote trade and cultural exchanges.

Detente was a strategic response to the Cold War's earlier periods of high tension, where conflicts and confrontations were prevalent. The goal of this approach was to create a more stable and peaceful international environment, reducing the likelihood of nuclear confrontation.

The other terms do not accurately describe this period. Containment refers to the U.S. policy aimed at preventing the spread of communism during the Cold War. Isolationism describes a foreign policy approach where a country seeks to avoid involvement in international affairs, particularly conflicts. Imperialism involves extending a country's power and influence through diplomacy or military force, which does not align with the concepts of reduced tension and engagement evident during Detente.