The feudal system is based on a sort of wealth hierarchy. The king gives land to nobles and in return they pay taxes. The nobles tax the peasants that move onto the land. The peasants are generally farmers, so they grow most, if not all their food. They sell the food to other peasants and nobles. The knights living on the land have an immediate duty to protect their kingdom is called on by the king, so they have less, or no taxes.
Eisenhower attempted to stop the spread of communism during the Cold War (this is called containment). The US feared that if one country started toward communism, other would follow suit.
