What idea was at the core of the "containment" policy established during the Cold War?

The core idea of the "containment" policy was to prevent the spread of communism. This doctrine emerged in the aftermath of World War II, as the Soviet Union began to expand its influence in Eastern Europe and other parts of the world. U.S. policymakers, notably George F. Kennan, articulated the need to "contain" Soviet power and prevent it from further encroaching into regions where it could destabilize governments and threaten democratic ideals.

The United States aimed to halt the expansion of communism through various means, including military alliances, economic aid strategies such as the Marshall Plan, and direct military intervention, as seen in conflicts like the Korean War. This strategic approach shaped much of U.S. foreign policy during the Cold War and influenced many of the nation's actions and decisions on the global stage.

While promoting global trade, supporting colonial independence, and encouraging disarmament negotiations were important issues during the Cold War, they were not the central focus of the containment policy, which remained steadfast in its mission to counter Soviet influence and communism specifically.