This is one of the greatest endings in the history of TV series :
At the end of Game of Thrones, Snow kills his lover Dragon Mother.
The dream of the dragon mother is to save all the slaves and commoners in the world, "break the wheel of power", kill all the old schools, and build a brave new world where everyone is equal.
Snow doesn't believe in that brave new world, and he doesn't agree with the sea of corpses and blood that leads to the brave new world.
The dragon mother, who claims to save the world, rides a giant dragon to fight everywhere, setting fire to the city along the way, and killing countless people in the war.
Even her advisor Little Devil sighed: The Dragon Mother, who represents justice, kills more people than any big villain.
Justice means slaughter, freedom means slavery, and equality means that all people accept the rule of the Dragon Mother. This is the icy logic behind the fiery idealism of the dragon mothers, another song of ice and fire.
While the radicals look to heaven in the distance, the conservatives see a path to slavery.
Before Snow started, he had such a conversation with the dragon mother:
Dragon Mother: The world we need cannot be built by people who are loyal to the old world. (Meaning to eliminate the opposition).
Snow: What we need is a benevolent world.
Dragon Mother: Pioneering is not an easy task, especially in the face of an unknown world, a beautiful world.
Snow: How do you know that the world is good?
Dragon Mother: I know what is good.
Snow: What about the others? Others who have their own opinions on "good".
Dragon Mother: They don't have a choice. 
There was no other choice, including the northern realm that disobeyed the rule of the Dragon Mother, including Snow's younger siblings and countless old relatives and friends, as well as those who were executed by the Dragon Mother, even the former close minister Wallis, who had been reduced to ashes in her thunderous rage.
To see oneself as the embodiment of truth and to look at others is a fallacy; Think of yourself as a messenger of justice, and those who oppose it deserve to die. These two self-righteous states of mind are not actually terrible, what is terrible is that people with this mentality have the most powerful violence at the same time.
Thankfully, Snow made a timely move. Otherwise, the future of Westeros is "Animal Farm"; The sequel to A Song of Ice and Fire is "1984".