Orwell gives the dominant pig the name Napoleon as a strong and obvious allusion to Napoleon Bonaparte. Napoleon Bonaparte, the egomaniac, emerged from the French Revolution as leader and spokesman of the ideals that inspired that earlier revolution. Under his leadership the French withstood the reactionary forces seeking to overturn the revolutionary government and restore the monarchy. But then Napoleon Bonaparte began to act like a dictator. He appointed himself Emperor and began making kings of his relatives. He was actually creating a new aristocracy based on allegiance to himself. Since Napoleon the pig represents Stalin, the obvious implication is that Stalin was creating a new aristocracy which was made up of the leaders and members of the Communist Party; and like Napoleon Bonaparte, Stalin was using revolutionary ideals and military power to spread Communism as far as possible. History was repeating itself.
Orwell presents Napoleon as a character bent on gaining then protecting a position of power.
With only one rival on the farm, Snowball, Napoleon seizes power as a totalitarian leader by chasing Snowball away. This episode features a warning on "state education":
Napoleon, the sinister pig tyrant, is carefully educating the dogs for his own evil purposes.
Indoctrinating the dogs, Napoleon creates his own enforcement agency that freely chooses to do his bidding, however violent and unjust. He then uses propaganda to alter the facts of recent history.
Each of these actions from Napoleon can be paralled in contemporary global politics (the elimination of political rivals, the use of state indoctrination and the use of propaganda and evasive/revisionary language).
Not all leaders are corrupt and not all leaders work against the ideas of open debate, representative democracy, and the ideals of government as the primary support and protection of liberty. But the leaders who do work against these notions have a thing or two in common with Napoleon, a pig whose plans ignore the welfare of the population and who is perfectly willing to gain from the pain of his subjects.