The concept of the Third World emerged after 1945 as a way to refer to the developing regions of the world, most often encompassing Africa, Asia, the Middle East, and Latin America. As a descriptive shorthand, the Third World entered common usage to contrast these regions from the capitalist “First World” and the communist “Second World,” even though some nations in these regions overtly aligned with one of the superpowers while others did not ascribe to such classifications. The term thus defies easy categorization and was used by historical actors to reflect different political and economic understandings of their geopolitical status. In the latter half of the 20th century, the Third World also gained purchase among some political leaders to describe non-Western, anti-imperialist, and anti-racist nations that had gained their independence from colonial rule and worked together to resist Cold War alignment. However, Third World leaders struggled to sustain their transnational solidarity, sometimes dividing along the lines of the broader superpower rivalry, regional or sectarian conflicts, and differing aspirations for world order.
US relations with the Third World were often fraught and complex. The United States did not maintain a single policy toward the Third World as such, reflective of its enormous diversity in language, culture, and politics. Instead, the United States devised foreign policies toward Third World nations according to different perceived imperatives and interests. A major theme in the history of US relations with the Third World was the US government’s overarching effort after World War II to undermine the spread of international communism, against which it deployed a wide range of military, political, social, and economic tools. In kind, Third World political leaders often strove to evade direct control by the United States and entered into diplomatic relations cognizant of the power asymmetries at work in the international system. In the 21st century, scholars and policymakers continue to use the Third World term, though it is often used interchangeably with the Global South and the underdeveloped, developing, and non-Western world.