The Cold War is another theme in the poem. Historians often date the Cold War from the end of World War II until 1989, with the opening of the Berlin Wall and the collapse of the Soviet Union. The term refers to the struggle for power between Western powers and Communist countries during this time. The nuclear arms race between the Soviet Union and the United States is a direct result of the Cold War, and the scenarios Tate satirically describes would not be imaginable without the race. In the second half of the twentieth century, many of the images and much of the discourse on nuclear war in popular culture assumed it would result from a clash between the superpowers.