Many actors crowd the stage of Cold War history: political leaders, mass movements, economic and military forces, ideologies, technologies, cultures, and identities. The role of transnational organizations may seem minor by comparison. Yet much evidence suggests that these groups helped keep the Cold War from turning into a hot war and contributed to the peaceful resolution of the East–West conflict and the nuclear arms race that represented its most dangerous component. Transnational contacts often contributed to an atmosphere conducive to the improvement of East–West relations, and sometimes transnational activists influenced specific decisions of governments by, for example, suggesting particular initiatives to resolve conflicts or move forward stalemated negotiations.

Transnational relations have been defined as “regular interactions across national boundaries when at least one actor is a non-state agent or does not operate on behalf of a national government or an intergovernmental organization.” The concept is intended to capture the phenomenon that many have observed of ordinary citizens involving themselves in issues that used to be the exclusive preserve of governments, or promoting new issues, such as the environment or human rights, onto the agenda of interstate relations. Such citizen-activists formed networks across borders, established sister-city relationships, and engaged in “track-two diplomacy” as an alternative to the official negotiations of government diplomats. The definition also encompasses regular interactions between state agents of one country and people of no official status in another, or between former and/or future government officials.