Here's what I believe Sasuke is saying:
In the shinobi world, war/killing occurs frequently.
Sasuke's saying that, the ancestors created a framework - a structural plan. This framework refers to the creation villages (a structure with their own concepts, values, and practices that constitutes their way of living): Hidden Leaf, Mist, Stone, Cloud, Sand and others in order to put an end to the countless killings among clans and children. Each villages are then lead or represented by a kage. According to Sasuke, the definition of a kage is someone who protects his country and ensures that peace is maintained by any means necessary, even if it means shouldering the hatred of everyone and not being accepted by anyone. Being alone. Itachi was this Kage, the True Hokage. Bringing peace only to Konoha. Itachi did it; not the other so-called Hokages that are acknowledged by everyone. But Itachi was not perfect, he had a bond that hampered him, his little brother: Sasuke.
Sasuke is now going to be an improved Itachi, a True Hokage v2.0 - A True Kage. He'll be following his brother's footstep. He'll be doing anything necessary to achieve peace. Itachi achieved peace by getting rid of the problem: the Uchiha Clan. Sasuke will achieve peace by also getting rid of the problems: the Kages and the tailed beasts.
According to him, Itachi could've been perfect, but he failed to eliminate his bond. Sasuke will eliminate his bond: Naruto. Having no ties or bond is very critical to achieving peace. He'll bring peace, not only to Konoha and the Fire Country, but to the entire shinobi world.