Yeah, those are just pretty words without the power to enforce them, like everything else the UN does
Yes. Nobody directly enforces the policy papers or the Declaration of Independence. That doesn’t mean they don’t have corporeal value. In part, due to being translated into laws.
The feeling of defending territory is natural and is not words
Only what constitutes the territory to defend has been warped by words.
Human food preferences are also just an idea by this standard.
A hunter gatherer tribe failing to defend its territory could result in its death just the same as not acquiring and eating appropriate food.
The need to defend might be a necessity for survival, but the desire to defend additional territory and resources has existed ever since humans have acquired the power to achieve more than the means of mere survival. Similar to food preferences, which become peculiar if there is plentitude, basic if tight, and sub-par in emergencies: during famines, sometimes people resort to eat grass to sate their feeling of hunger even though digesting it is an energetic net negative.
Not true. Patriotism is very real. It's an affection for a group of people and for the ideals of those people. To some lesser extent it's also love for the geography of your land. But patriotism is rarer in the west than it once was. Also, if a country's territory is invaded by an enemy, at least some of its people will go to fight to protect their families from the oncoming enemies.