This question deals with the themes concerning power in this novel. Napoleon is struggling at the beginning to take control of Animal Farm. He is battling for dominance with Snowball, who seems to oppose him on every issue.
Napoleon exerts his power in this novel by the same means in which he establishes it to begin with, force. He takes the dogs away from their mother and "educates" them in private where he trains them to obey him alone. These dogs become his force. They chase off Snowball so Napoleon can take control, and when some of the other pigs begin to object, the dogs "growl threateningly" and shut everyone up. Napoleon also exerts his power by eliminating everyone who stands against him. He kills anyone who might possibly become a threat to his supremacy.
Napoleon manipulates the other animals as well. He takes advantage of the fact that they are not smart enough to catch him in his lies. He changes the "Commandments" knowing that the other animals will not be able to prove anything. He oppresses the other animals, just like Jones before him, by working them so hard they lack the energy to revolt. He also shuts down all the education classes for older animals so they cannot educate themselves and see what is really going on.