The passage from the Truman Doctrine shows the domino theory because C. It demonstrates the belief that the future of one country will affect others as well.
This was a belief by the United States that when a country became Communist, it would allow for the countries around it to become communist as well.
This means that the future of a nation is linked to those of others and Truman shows this by talking about how the future of Greece will affect Turkey and the Middle East.
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