Explain how foreign affairs were guided by national self-interest. ( provide two examples)

In general, foreign affairs are always guided by self-interest, since a country would not want to get involved in the affairs of another without there being some domestic benefit. One such example would be the US involvement in Vietnam, since it was thought that this would discourage the spread of communism, which was the enemy of capitalism. Another example would be the US involvement in WWII, since the spread of fascism was frightening to many.