Staring at a wall

How do you determine the boundary of a room?
How do you add internal ambiance?
How do you provide stability?
A wall.

How do you gain privacy?
How do you stop the flow of liquids?
How do you alter the socio-economic dynamic of a city or state?
A wall.

What's tall?
What's long?
What are usually made of brick or stone?
A wall.

What shouldn't be political?
What should maintain it's integrity, despite opposition?
What has been proven to be beneficial for almost every society that employs them?
Poetry... and walls.