According to the memorandum, which of the following best explains the root of the tensions between the Soviet Union and the United States?
The building of the Berlin Wall to divide the former German capital into West and East occupation zones
The successful launch of Sputnik I, the first successful artificial satellite, by the Soviet Union
The inherent conflict between capitalist and communist economic policies, markets, and trade
The Soviet fear of world conflicts due to interference from the United States in communist nations