That's false. The Muslims won the Crusades.
Answer:
Nuclear Arms race.
Extensive spying techniques.
Proxy Wars were fought under the influence of the two world powers.
Explanation:
Both countries have used comprehensive methods of spying against each other. It is estimated that in all of the numerous proxy wars waged between the United States of America and the Soviet Union, more than eleven million civilians were killed. The U.S. had a national intelligence agency named the Central Intelligence Agency (CIA) and the Soviets had the KGB. The Space Race emerged from the Cold War and the Internet was a direct result of that. During the Cold War there was a spike in nuclear weapons.
Well you can rule out communism since that is not an economic system but a system of government. Socialism is the answer you are looking for. Socialism involves the division of everything into equal parts. No economic classes is a major trait of Socialism.