[falcolas]

> To believe that borders are conducive to peace sounds like a bad case of internet-brain.

There's an old saying about this: "Good Fences make Good Neighbors". A fence (border) make it easy to say "you can't plant that tree there."

Borders (largely) define where one government can affect resources claimed by another government. For example, it would suck if it was easy for the US to send loggers into Canada's forests because the US claims that those forests belong to them. A border makes it clear that "forest X is within Canada's borders, and thus belongs to Canada".

The location of the border may still be disputed, but it simplifies a lot of other interactions.

On the flip side, borders also make it easier to create accountability for a resource (like who maintains roads near/between countries).