Nations are not lines on a map.
If you walk from Los Angeles to East Texas when you get there you will be fine. The words might mean something different, the food is different and who knows what they believe in. If I walk from Redlands to Mexico how do I know when I get there? Are there areas where the language is different, the food is different and the clothing is different?
The same is true in Los Angeles where the concept is very easy to illustrate. When you walk from Monterey Park to Long Beach Via Downtown LA will that happen to you? Will you turn a corner and all of a sudden the signs are in a different language? People look different? You can’t understand a word they say? The food smells good but you have no idea what the names mean? Does it sound the same? If that happens to you, you are in a different nation with a small n. VS a Nation with a large N.