the United States and the Soviet Union develop into superpowers during the 20th century while Europe, which had been the primary location of international power during the 19th century, fade in influence?

In a four-page essay, double spaced with one-inch margins, please answer the following question- Why did the United States and the Soviet Union develop into superpowers during the 20th century while Europe, which had been the primary location of international power during the 19th century, fade in influence?
You can use outside sources for this paper.