^ people downvoting your comment are wrong; it's completely true. The nation-state is a martial construct; the difference between it and its neighbors is a line of demarcation upheld by an external-facing military, and its own legitimacy, economy, and system of laws and conflict resolution is enforced on the populace via an internal-facing "military" (police force).

(Edit: when I wrote this the parent comment was light grey, but now it's back to black. Perhaps it's a controversial comment.)