Earlier quoted context omitted.
unfortunately, i don't know of any single border of any state or nation that was peacefully acquired or constituted. I don't think "modernity" has changed anything, no matter where you make it starts. If you want an example, then look at Israel, which is one of the first state that wasn't created unilaterally through force or as a result of war, but (at least initially) through a UN resolution from an assembly of sta…
Israel was totally created from war, the 1948 war, and the 1967 war.
The fact that this declaration was accepted by a majority of states including the most powerful ones, and yet lead to an immediate never-ending war is the point i was trying to make. To my knowledge, borders always get determined through war, even if you try to begin with a legal procedure.