It helped everything happen faster and more efficiently
Austria-Hungary was home to many ethnic groups
Answer:
Columbus was the first explorer
After fighting the war in Korea, the US had learned that communism would spread. In order to keep with their policy of containment, they had to rush in and stop Viet Cong from spreading communism (much like the domino theory that the US had). Had Viet Cong not wanted to bring about communism, there would be no need for invasion, and the domino theory would have yet to be proven.
:)
The causes of the French Revolution were complicated, but if you were to pick one, a good thesis would be that the American Revolution was highly influential in sparking the French Revolution.