Final answer:
The Allies during World War II promoted cooperation and the prevention of aggression through the Atlantic Charter, and post-war, they formed military alliances like NATO to maintain security and peace.
Step-by-step explanation:
During World War II, the Allies promoted the ideas of cooperation and the prevention of aggression to maintain world peace. One of the key documents articulating these goals was the Atlantic Charter, which resulted from meetings between Roosevelt and Churchill. This document outlined principles such as free access to markets, disarmament, democracy, and self-determination.
Although critics argued that these principles were not applied to all territories, particularly colonies, the intent was to shape a post-war world that could avoid future conflicts through these measures. The Allies backed these ideals by forming military alliances like the North Atlantic Treaty Organization (NATO) after the war, creating a new security landscape in Europe and setting the stage for the Cold War.