This happens because people don't trust each other. I don't mean just regular people, but humanity in general is not so trusting of those outside the tribe, whi

This happens because people don't trust each other. I don't mean just regular people, but humanity in general is not so trusting of those outside the tribe, which is a country in this case today. Therefore, even though it is inefficient, countries will vie to have higher and higher military power (or ally with one who does) because the threat of violence is often as good as violence itself.